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Shujun Zhang - One of the best experts on this subject based on the ideXlab platform.
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High-Performance Sm-Doped Pb(Mg1/3Nb2/3)O3-PbZrO3-PbTiO3-Based Piezoceramics.
ACS applied materials & interfaces, 2019Co-Authors: Qinghu Guo, Hanxing Liu, Fangquan Xia, Xiaoyi Gao, Pengbin Wang, Hua Hao, Huajun Sun, Shujun ZhangAbstract:High-performance piezoelectric materials are pivotal to many electromechanical applications including piezoelectric actuators, sensors, and transducers. However, the general approach to achieve high piezoelectric properties by establishing morphotropic phase boundary (MPB) has limitation due to the weak anisotropy of the Gibbs free energy profile at the MPB region. Here, aliovalent Sm3+-doped 0.4Pb(Mg1/3Nb2/3)O3-(0.6-x)PbZrO3-xPbTiO3 piezoelectric ceramics were fabricated by a solid-state method, where the optimized piezoelectric coefficient d33 = 910 pC/N, dielectric constant er = 4090, and Curie temperature TC = 184 °C were obtained at x = 0.352, being attributed to the synergistic Contributions from the MPB and enhanced local structural heterogeneity. Rayleigh analysis was adopted to study the intrinsic and Extrinsic Contributions in Sm-doped PMN-PZ-PT ceramics, where the Extrinsic Contribution was found to be on the order of 25-67% at 4 kV/cm. Of particular significance is that a large signal d33* = 820 pm/V (at 20 kV/cm) with a minimal strain variation of 5% was achieved for a composition of x = 0.372 over the temperature range of 20-160 °C, being superior to those previously reported piezoelectric ceramic materials. This work offers a good paradigm to simultaneously achieve high piezoelectric properties with good temperature stability in ferroelectric ceramics, which have great potential for piezoelectric application at elevated temperatures.
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High-Performance Sm-Doped Pb(Mg₁/₃Nb₂/₃)O₃-PbZrO₃-PbTiO₃-Based Piezoceramics
ACS Applied Materials & Interfaces, 2019Co-Authors: Qinghu Guo, Hanxing Liu, Fangquan Xia, Xiaoyi Gao, Pengbin Wang, Hua Hao, Huajun Sun, Shujun ZhangAbstract:High-performance piezoelectric materials are pivotal to many electromechanical applications including piezoelectric actuators, sensors, and transducers. However, the general approach to achieve high piezoelectric properties by establishing morphotropic phase boundary (MPB) has limitation due to the weak anisotropy of the Gibbs free energy profile at the MPB region. Here, aliovalent Sm³⁺-doped 0.4Pb(Mg₁/₃Nb₂/₃)O₃-(0.6–x)PbZrO₃-xPbTiO₃ piezoelectric ceramics were fabricated by a solid-state method, where the optimized piezoelectric coefficient d₃₃ = 910 pC/N, dielectric constant eᵣ = 4090, and Curie temperature TC = 184 °C were obtained at x = 0.352, being attributed to the synergistic Contributions from the MPB and enhanced local structural heterogeneity. Rayleigh analysis was adopted to study the intrinsic and Extrinsic Contributions in Sm-doped PMN-PZ-PT ceramics, where the Extrinsic Contribution was found to be on the order of 25–67% at 4 kV/cm. Of particular significance is that a large signal d₃₃* = 820 pm/V (at 20 kV/cm) with a minimal strain variation of 5% was achieved for a composition of x = 0.372 over the temperature range of 20–160 °C, being superior to those previously reported piezoelectric ceramic materials. This work offers a good paradigm to simultaneously achieve high piezoelectric properties with good temperature stability in ferroelectric ceramics, which have great potential for piezoelectric application at elevated temperatures.
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domain configuration and thermal stability of k0 48na0 52 nb0 96sb0 04 o3 bi0 50 na0 82k0 18 0 50zro3 piezoceramics with high d33 coefficient
ACS Applied Materials & Interfaces, 2016Co-Authors: Jialiang Zhang, Chaojing Lu, Shujun ZhangAbstract:The domain configuration of lead-free (K0.48Na0.52)(Nb0.96Sb0.04)O3–Bi0.50(Na0.82K0.18)0.50ZrO3 ceramics with rhombohedral–tetragonal morphotropic phase boundary, accounting for the high piezoelectric property and good thermal stability, were systematically studied. Short domain segments (before poling) and long domain stripes with wedge-shaped or furcated ends (after poling) were found to be typical domain configurations. The reduced elastic energy, lattice distortion, and internal stress, due to the coexistence of rhombohedral and tetragonal phases, result in much easier domain reorientation and domain wall motion, responsible for the high piezoelectric properties, being on the order of 460 pC/N, in which the Extrinsic Contribution from irreversible domain switching was estimated to be around 50% of the total piezoelectricity. Minor piezoelectric property variations (<6% over a temperature range from −50 to 100 °C) were observed as a function of temperature, showing a good thermal stability. In addition...
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Domain Structure of Potassium‐Sodium Niobate Ceramics Before and After Poling
Journal of the American Ceramic Society, 2014Co-Authors: Yalin Qin, Jialiang Zhang, Weizeng Yao, Chunlei Wang, Shujun ZhangAbstract:Domain structure and domain wall motion play important roles on the piezoelectric properties of ferroelectric ceramics. In this work, the domain structure of hot-pressed (K0.50Na0.50)NbO3 (KNN) ceramics before and after poling were studied by observing the domain patterns with an acid-etching technique, and the Extrinsic Contribution to the piezoelectric properties were evaluated. It was found that the domain structure of the unpoled KNN ceramic was relatively complicated with many watermark, herringbone and zigzag patterns, while only a single set or few sets of parallel domain stripes were observed in the poled KNN ceramic, due to the domain reorientation and domain wall motion during the poling process. The average domain width changes from 200 (±10) nm before poling to 250 (±10) nm after poling. Domain configurations of “Herringbone-Zigzag-Watermark” and “Herringbone- Herringbone-Zigzag” types observed in the unpoled KNN ceramic were then further analyzed. The Extrinsic Contribution to the piezoelectric properties from the domain reorientation and irreversible domain wall motion in the hot-pressed KNN ceramic was found to be 71%, slightly higher than that of conventional sintered KNN ceramics ~68%.
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Investigation of dielectric and piezoelectric properties in Pb(Ni1/3Nb2/3)O3-PbHfO3-PbTiO3 ternary system
Journal of The European Ceramic Society, 2013Co-Authors: H Tang, Min Zhang, Shujun Zhang, Ying Feng, Thomas R. ShroutAbstract:Abstract The dielectric and piezoelectric properties were investigated in the (1 − x)Pb(Hf1−yTiy)O3–xPb(Ni1/3Nb2/3)O3 (PNN–PHT, x = 0.05–0.50, y = 0.55–0.70) ternary system. The morphotropic phase boundary (MPB) was determined by X-ray powder diffraction analysis. Isothermal map of Curie temperature (TC) related to the compositions in the phase diagram was obtained. The optimum dielectric and piezoelectric properties were achieved in ceramics with the MPB compositions, with the maxima values being on the order of 6000 and 970pC/N, respectively. Rayleigh analysis was used to study the Extrinsic Contribution (domain wall motion) in PNN–PHT system, where the Extrinsic Contribution was found to be ∼30% for composition 0.49PNN–0.51PHT(30/70), showing a high nonlinearity.
Thomas R. Shrout - One of the best experts on this subject based on the ideXlab platform.
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Investigation of dielectric and piezoelectric properties in Pb(Ni1/3Nb2/3)O3-PbHfO3-PbTiO3 ternary system
Journal of The European Ceramic Society, 2013Co-Authors: H Tang, Min Zhang, Shujun Zhang, Ying Feng, Thomas R. ShroutAbstract:Abstract The dielectric and piezoelectric properties were investigated in the (1 − x)Pb(Hf1−yTiy)O3–xPb(Ni1/3Nb2/3)O3 (PNN–PHT, x = 0.05–0.50, y = 0.55–0.70) ternary system. The morphotropic phase boundary (MPB) was determined by X-ray powder diffraction analysis. Isothermal map of Curie temperature (TC) related to the compositions in the phase diagram was obtained. The optimum dielectric and piezoelectric properties were achieved in ceramics with the MPB compositions, with the maxima values being on the order of 6000 and 970pC/N, respectively. Rayleigh analysis was used to study the Extrinsic Contribution (domain wall motion) in PNN–PHT system, where the Extrinsic Contribution was found to be ∼30% for composition 0.49PNN–0.51PHT(30/70), showing a high nonlinearity.
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domain size engineering in tetragonal pb in1 2nb1 2 o3 pb mg1 3nb2 3 o3 pbtio3 crystals
Journal of Applied Physics, 2011Co-Authors: Shujun Zhang, Jun Luo, Dabin Lin, Zhenrong Li, Fei Li, Zhuo Xu, Satoshi Wada, Thomas R. ShroutAbstract:The effect of domain size on the dielectric and piezoelectric properties of [111]-oriented tetragonal Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals was investigated. The dielectric permittivity (ɛ33 T/ɛ0) and piezoelectric coefficient (d33) were found to be on the order of 13 800 and 1630 pC/N, respectively, for samples with domain size of ∼500 nm, a 3-fold increase to crystals with domain size of ∼50 μm. Rayleigh analysis revealed that the Extrinsic Contribution to the piezoelectric response increased from ∼8% to 30% with decreasing domain size, due to the increased domain wall density and associated irreversible domain wall motion. The enhanced properties were thought to relate to the fine domain structures, however, showing a poor electric field and temperature stabilities with domain size of 500 nm. Of particular significance is that samples with domain size being on the order of 5 μm exhibit field and temperature stabilities, with yet high piezoelectric properties, make it potential for transduce...
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Piezoelectric activity of relaxor-PbTiO3 based single crystals and polycrystalline ceramics at cryogenic temperatures: Intrinsic and Extrinsic Contributions
Applied physics letters, 2010Co-Authors: Shujun Zhang, Xiaoyong Wei, Jun Luo, Thomas R. ShroutAbstract:The piezoelectric activity in [001] poled Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 crystals was investigated as a function of composition and temperature. The level of intrinsic and/or Extrinsic Contribution to the total piezoelectric activity was analyzed using Rayleigh method. The results revealed that though 95% of the observed piezoelectric activity in rhombohedral crystals was intrinsic (lattice), the properties decreased significantly with decreasing temperature. At −150 °C, the piezoelectric response decreased by 40%–55% for the compositions close to a morphotropic phase boundary (rhombohedral-monoclinic or monoclinic-tetragonal), while decreasing only 20%–30% for the compositions in the rhombohedral region. The piezoelectric properties of Pb(Mg1/3Nb2/3)O3–PbTiO3 polycrystalline ceramics were found to decrease by 75%, showing both intrinsic and Extrinsic Contributions play important role in the reduction in piezoelectricity at cryogenic temperatures for ceramics.
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intrinsic and Extrinsic size effects in fine grained morphotropic phase boundary lead zirconate titanate ceramics
Journal of the American Ceramic Society, 2005Co-Authors: Clive A Randall, Johnpaul Kucera, Thomas R. ShroutAbstract:The processing, electromechanical properties, and microstructure of lead zirconate titanate (PZT) ceramics over the grain-size range of 0.1-10 μm were studied. Using measurements over a large temperature range (15-600 K), the relative role of Extrinsic Contribution (i.e., domain-wall motion) was deduced to be influenced strongly by the grain size, particularly for donor-doped PZT. Analytical transmission electron microscopy studies were conducted to investigate the trend in domain configurations with the reduction of grain size. The correlations between domain density, domain variants, domain configurations (before and after poling), spontaneous deformation, and the elastodielectric properties were qualitatively discussed, leading to new insights into the intrinsic and Extrinsic effects and relevant size effects in ferroelectric polycrystalline materials.
S K Streiffer - One of the best experts on this subject based on the ideXlab platform.
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evaluation of intrinsic and Extrinsic Contributions to the piezoelectric properties of pb zr1 xtx o3 thin films as a function of composition
Journal of Applied Physics, 2003Co-Authors: Dongjoo Kim, Jonpaul Maria, A I Kingon, S K StreifferAbstract:The piezoelectric, dielectric, and ferroelectric properties of highly (111)-textured, 200-nm-thick polycrystalline lead zirconate titanate (PZT) films have been investigated as a function of Zr/Ti ratio. The distinct peak in piezoelectric coefficient at the morphotropic phase boundary found in bulk PZT ceramics is not observed in thin film PZTs. Measurements of the temperature dependence of relative permittivity and the nonlinear behavior of relative permittivity and piezoelectric coefficient suggest that non-180° domain wall motion in these films is negligible, indicating that the Extrinsic Contribution to the room temperature permittivity is dominated by only 180° domain wall motion. The semiempirical phenomenological equation relating the piezoelectric coefficient to measured polarization and permittivity values is demonstrated to give an excellent description of the piezoelectric behavior in these films, assuming bulk electrostrictive and elastic coefficients. The small deviation between calculated an...
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Evaluation of intrinsic and Extrinsic Contributions to the piezoelectric properties of Pb(Zr1-xTx)O3 thin films as a function of composition
Journal of Applied Physics, 2003Co-Authors: Dongjoo Kim, Jonpaul Maria, A I Kingon, S K StreifferAbstract:The piezoelectric, dielectric, and ferroelectric properties of highly (111)-textured, 200-nm-thick polycrystalline lead zirconate titanate (PZT) films have been investigated as a function of Zr/Ti ratio. The distinct peak in piezoelectric coefficient at the morphotropic phase boundary found in bulk PZT ceramics is not observed in thin film PZTs. Measurements of the temperature dependence of relative permittivity and the nonlinear behavior of relative permittivity and piezoelectric coefficient suggest that non-180° domain wall motion in these films is negligible, indicating that the Extrinsic Contribution to the room temperature permittivity is dominated by only 180° domain wall motion. The semiempirical phenomenological equation relating the piezoelectric coefficient to measured polarization and permittivity values is demonstrated to give an excellent description of the piezoelectric behavior in these films, assuming bulk electrostrictive and elastic coefficients. The small deviation between calculated and measured piezoelectric coefficients as well as the dependence of piezoelectric and polarization behavior on the external field, i.e., hysteresis loop, are suggested to be primarily due to backswitching of 180° domains.
Dongjoo Kim - One of the best experts on this subject based on the ideXlab platform.
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Compositional Effects on the Piezoelectric and Ferroelectric Properties of Chemical Solution Deposited PZT Thin Films
MRS Online Proceedings Library, 2011Co-Authors: Dongjoo Kim, Jonpaul Maria, A I KingonAbstract:The piezoelectric, dielectric, and ferroelectric properties of highly (111)-textured polycrystalline lead zirconate titanate (PZT) films as a function of Zr/Ti composition have been investigated. The peak in piezoelectric coefficient at the morphotropic phase boundary (MPB) observed in bulk PZT ceramics has not been found in thin film PZTs. Measurement of the piezoelectric response as a function of AC amplitude suggests that non-180° domain wall motion in these films is negligible, indicating that the Extrinsic Contribution to the room temperature dielectric constant is dominated by only 180° domain wall motion. The semi-empirical phenomenological equation relating the piezoelectric coefficient to measured polarization and permittivity values is demonstrated to give an excellent description of the piezoelectric behavior in these films, assuming bulk electrostrictive coefficients. The small deviation between calculated and measured piezoelectric coefficients as well as the dependence of piezoelectric and polarization behavior on the external dc field, i.e., hysteresis loop, are suggested to be primarily due to backswitching of 180° domains.
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evaluation of intrinsic and Extrinsic Contributions to the piezoelectric properties of pb zr1 xtx o3 thin films as a function of composition
Journal of Applied Physics, 2003Co-Authors: Dongjoo Kim, Jonpaul Maria, A I Kingon, S K StreifferAbstract:The piezoelectric, dielectric, and ferroelectric properties of highly (111)-textured, 200-nm-thick polycrystalline lead zirconate titanate (PZT) films have been investigated as a function of Zr/Ti ratio. The distinct peak in piezoelectric coefficient at the morphotropic phase boundary found in bulk PZT ceramics is not observed in thin film PZTs. Measurements of the temperature dependence of relative permittivity and the nonlinear behavior of relative permittivity and piezoelectric coefficient suggest that non-180° domain wall motion in these films is negligible, indicating that the Extrinsic Contribution to the room temperature permittivity is dominated by only 180° domain wall motion. The semiempirical phenomenological equation relating the piezoelectric coefficient to measured polarization and permittivity values is demonstrated to give an excellent description of the piezoelectric behavior in these films, assuming bulk electrostrictive and elastic coefficients. The small deviation between calculated an...
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Evaluation of intrinsic and Extrinsic Contributions to the piezoelectric properties of Pb(Zr1-xTx)O3 thin films as a function of composition
Journal of Applied Physics, 2003Co-Authors: Dongjoo Kim, Jonpaul Maria, A I Kingon, S K StreifferAbstract:The piezoelectric, dielectric, and ferroelectric properties of highly (111)-textured, 200-nm-thick polycrystalline lead zirconate titanate (PZT) films have been investigated as a function of Zr/Ti ratio. The distinct peak in piezoelectric coefficient at the morphotropic phase boundary found in bulk PZT ceramics is not observed in thin film PZTs. Measurements of the temperature dependence of relative permittivity and the nonlinear behavior of relative permittivity and piezoelectric coefficient suggest that non-180° domain wall motion in these films is negligible, indicating that the Extrinsic Contribution to the room temperature permittivity is dominated by only 180° domain wall motion. The semiempirical phenomenological equation relating the piezoelectric coefficient to measured polarization and permittivity values is demonstrated to give an excellent description of the piezoelectric behavior in these films, assuming bulk electrostrictive and elastic coefficients. The small deviation between calculated and measured piezoelectric coefficients as well as the dependence of piezoelectric and polarization behavior on the external field, i.e., hysteresis loop, are suggested to be primarily due to backswitching of 180° domains.
C Bouard - One of the best experts on this subject based on the ideXlab platform.
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large enhancement of the spin hall effect in au by side jump scattering on ta impurities
Physical Review B, 2017Co-Authors: P Laczkowski, Yu Fu, Huaiwen Yang, J C Rojassanchez, P Noel, V T Pham, G Zahnd, C Deranlot, S Collin, C BouardAbstract:We present measurements of the Spin Hall Eect (SHE) in AuW and AuTa alloys for a large range of W or Ta concentrations by combining experiments on lateral spin valves and Ferromagnetic-Resonance/spin pumping technique. The main result is the identication of a large enhancement of the Spin Hall Angle (SHA) by the side-jump mechanism on Ta impurities, with a SHA as high as + 0.5 (i.e 50%) for about 10% of Ta. In contrast the SHA in AuW does not exceed + 0.15 and can be explained by intrinsic SHE of the alloy without signicant Extrinsic Contribution from skew or side-jump scattering by W impurities. The AuTa alloys, as they combine a very large SHA with a moderate resistivity (smaller than 85 µΩ.cm), are promising for spintronic devices exploiting the SHE. A goal of spintronics is to generate, manipulate and detect spin currents for the transfer and manipulation of information, thus allowing faster and low-energy consuming operations. Since the discovery of the Giant Magnetoresistance a "classical" way to produce spin currents was to take advantage of ferromagnetic materials and their two different spin channel conductivities [1, 2]. In the last decade the rediscovery and study of spin orbit interaction eects brought new insights into creation mechanisms of spin currents. Among all mechanisms the spin Hall eect (SHE) focused a lot of attention as it allows the generation of spin currents from charge current and vice versa [3]. Despite being observed only a decade ago [46] these eects are already ubiquitous within the Spintronics as standard spin-current generators and detectors [7 9]. The conversion coecient between charge and spin currents is called the spin Hall angle (SHA) and is dened as Θ SHE = ρ xy /ρ xx , ratio of the non-diagonal and diagonal terms of the resistivity tensor. One of the main interests of the SHE is to provide a new paradigm for Spintronics where non-magnetic materials becomes active spin current source and detector. Until now most of the reports focused on single heavy metals and intrinsic SHE mechanisms, the main materials of interest being: Pt, Ta, W, and some oxydes. With intrinsic mechanisms the SHA is typically proportional to the resistivity of the heavy metal, and generally, a large value of the SHA is associated with a high resistivity (i.e.-0.3 for the SHA in β − W is associated with 263 µΩ.cm [10]) which limits the current density and the resulting spin transfer torques on the mag-netisation of an adjacent metallic ferromagnetic material. Extrinsic SHE mechanisms associated with the spin dependent scattering on impurities or defects are an alternative to generate transverse spin currents [11]. Two particular scattering mechanisms have been identied: the skew scattering [12] providing a non-diagonal term of the resistivity tensor proportional to the longitudinal resistivity (ρ xy ∝ ρ xx) and the side jump [13] for which the non-diagonal term is proportional to the square of the resistivity (ρ xy ∝ ρ 2 xx). For instance, the skew scattering mechanism have been observed in CuIr, CuBi, CuPb alloys (SHA=0.02,-0.24,-0.13, resp.) [14, 15]. The intrinsic mechanism from Berry curvature in the conduction band gives the same dependence ρ xy ∝ ρ 2 xx as the side-jump Contribution so that, for example the SHE of AuPt (SHA=0.3 at max.) alloys could be explained by a predominant intrinsic eect rather than ascribed to side-jump[16]. In this letter we present a study of Au-based alloys with W and T a impurities. We demonstrate that the side-jump scattering mechanism dominates in AuTa alloys, and generates high spin Hall angles (up to + 0.5) with the additional advantage of resistivities (ρ AuT a < 85µΩ.cm) smaller than in most materials with SHA in the same range. By contrast in AuW alloys the SHE is mainly due to only the intrinsic mechanism and is denitely smaller than in AuTa. This dierence between AuTa and AuW is supported by ab − initio calculations. The alloys were fabricated by DC magnetron sputtering by co-deposition of the two pure materials. The concentration in atomic purcent were determined by chemical analyzes (proton or electron induced X-ray emission) and from the depo-sition rate of each species. We control the alloy-ing through the increase of the resistivity as the
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Large enhancement of the spin Hall effect in Au by scattering with side-jump on Ta impurities
Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2017Co-Authors: P Laczkowski, Huaiwen Yang, P Noel, V T Pham, G Zahnd, C Deranlot, S Collin, C Bouard, J.-c. Rojas-sánchez, P WarinAbstract:We present measurements of the Spin Hall Eect (SHE) in AuW and AuTa alloys for a large range of W or Ta concentrations by combining experiments on lateral spin valves and Ferromagnetic-Resonance/spin pumping technique. The main result is the identication of a large enhancement of the Spin Hall Angle (SHA) by the side-jump mechanism on Ta impurities, with a SHA as high as + 0.5 (i.e 50%) for about 10% of Ta. In contrast the SHA in AuW does not exceed + 0.15 and can be explained by intrinsic SHE of the alloy without signicant Extrinsic Contribution from skew or side-jump scattering by W impurities. The AuTa alloys, as they combine a very large SHA with a moderate resistivity (smaller than 85 µΩ.cm), are promising for spintronic devices exploiting the SHE. A goal of spintronics is to generate, manipulate and detect spin currents for the transfer and manipulation of information, thus allowing faster and low-energy consuming operations. Since the discovery of the Giant Magnetoresistance a "classical" way to produce spin currents was to take advantage of ferromagnetic materials and their two different spin channel conductivities [1, 2]. In the last decade the rediscovery and study of spin orbit interaction eects brought new insights into creation mechanisms of spin currents. Among all mechanisms the spin Hall eect (SHE) focused a lot of attention as it allows the generation of spin currents from charge current and vice versa [3]. Despite being observed only a decade ago [46] these eects are already ubiquitous within the Spintronics as standard spin-current generators and detectors [7 9]. The conversion coecient between charge and spin currents is called the spin Hall angle (SHA) and is dened as Θ SHE = ρ xy /ρ xx , ratio of the non-diagonal and diagonal terms of the resistivity tensor. One of the main interests of the SHE is to provide a new paradigm for Spintronics where non-magnetic materials becomes active spin current source and detector. Until now most of the reports focused on single heavy metals and intrinsic SHE mechanisms, the main materials of interest being: Pt, Ta, W, and some oxydes. With intrinsic mechanisms the SHA is typically proportional to the resistivity of the heavy metal, and generally, a large value of the SHA is associated with a high resistivity (i.e.-0.3 for the SHA in β − W is associated with 263 µΩ.cm [10]) which limits the current density and the resulting spin transfer torques on the mag-netisation of an adjacent metallic ferromagnetic material. Extrinsic SHE mechanisms associated with the spin dependent scattering on impurities or defects are an alternative to generate transverse spin currents [11]. Two particular scattering mechanisms have been identied: the skew scattering [12] providing a non-diagonal term of the resistivity tensor proportional to the longitudinal resistivity (ρ xy ∝ ρ xx) and the side jump [13] for which the non-diagonal term is proportional to the square of the resistivity (ρ xy ∝ ρ 2 xx). For instance, the skew scattering mechanism have been observed in CuIr, CuBi, CuPb alloys (SHA=0.02,-0.24,-0.13, resp.) [14, 15]. The intrinsic mechanism from Berry curvature in the conduction band gives the same dependence ρ xy ∝ ρ 2 xx as the side-jump Contribution so that, for example the SHE of AuPt (SHA=0.3 at max.) alloys could be explained by a predominant intrinsic eect rather than ascribed to side-jump[16]. In this letter we present a study of Au-based alloys with W and T a impurities. We demonstrate that the side-jump scattering mechanism dominates in AuTa alloys, and generates high spin Hall angles (up to + 0.5) with the additional advantage of resistivities (ρ AuT a < 85µΩ.cm) smaller than in most materials with SHA in the same range. By contrast in AuW alloys the SHE is mainly due to only the intrinsic mechanism and is denitely smaller than in AuTa. This dierence between AuTa and AuW is supported by ab − initio calculations. The alloys were fabricated by DC magnetron sputtering by co-deposition of the two pure materials. The concentration in atomic purcent were determined by chemical analyzes (proton or electron induced X-ray emission) and from the depo-sition rate of each species. We control the alloy-ing through the increase of the resistivity as the
