The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Hatsuo Tange - One of the best experts on this subject based on the ideXlab platform.
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the Magnetovolume Effect of an amorphous magnet gd67ni33
Journal of the Physical Society of Japan, 2003Co-Authors: Ikuo Nakai, Hatsuo Tange, Kensuke Konishi, T Kamimori, Akifumi Chikazawa, Yasuhiro MotegiAbstract:We have observed a large Magnetovolume Effect in a melt spun Gd-rich amorphous magnet Gd 67 Ni 33 . The magnet shows the forced volume magnetostriction of a positive value of 3.76×10 -5 T -1 at 4.4...
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Magnetovolume Effect of fe sublattice in r2fe17
Journal of Magnetism and Magnetic Materials, 2001Co-Authors: T Kamimori, Kensuke Konishi, K Kinoshita, J Mochimaru, Hatsuo TangeAbstract:The measured Magnetovolume Effect of Fe sublattice in R 2 Fe 17 , dT c /dV and dM s /dV are 3.8 × 10 3 K/nm 3 and 1.8 × 10 1 μ B /nm 3 /Fe. However, these Magnetovolume Effects cannot explain the elevation of T c caused by the nitrogenation and the substitution of Si for Fe in Y 2 Fe 17 compounds. On the contrary, the Fe sublattice in R 2 Fe 14 Si 3 compounds has very small dT c /d dV. The elevation of T c is caused by the reduction of Invar properties of iron sublattice in the R 2 Fe 17 7 compounds.
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Forced-volume magnetostriction and thermal expansion in amorphous Gd65Co35
Physica B-condensed Matter, 1997Co-Authors: Ikuo Nakai, Hatsuo TangeAbstract:Abstract We have measured the forced-volume magnetostriction and the thermal expansion for an amorphous ferrimagnet Gd65Co35. It shows a small positive value of the forced-volume magnetostriction at 4.2 K and a large spontaneous-volume magnetostriction below the paramagnetic Curie temperature. Both of these volume magnetostrictions are proportional to the square of temperature. The Magnetovolume Effect of the ferrimagnet is mainly due to the change in the Co moment rather than the net magnetization.
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magnetization and Magnetovolume Effect of an amorphous gd80si12b8 alloy
Journal of Magnetism and Magnetic Materials, 1992Co-Authors: S Ishio, Hatsuo Tange, T Kamimori, T Miyazaki, S Negami, T Obara, M GotoAbstract:Abstract The magnetic properties and Magnetovolume Effects of amorphous (Gd x Fe 1−itx ) 80 Si 12 B 8 (0.7 ≦ x ≦ 1.0) alloys were investigated. Gd 80 Si 12 B 8 is the asperomagnet with the Curie temperature T c of 128 K. Asperomagnetic characters have faded away quickly by the substitution of Fe, and T c increases to about 247 K for x = 0.7. The pressure Effect on the magnetization (ϖ ln σ/ϖ P ) evaluated from the forced volume magnetostriction is about -8.8x10 -6 bar -1 for Gd 80 Si 12 B 8 .
T Goto - One of the best experts on this subject based on the ideXlab platform.
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Temperature dependence of Landau coefficients in Lu(Co1−xGax)2
Journal of Magnetism and Magnetic Materials, 2004Co-Authors: Fumihiro Ishikawa, T Goto, Kazuaki Fukamichi, H. YamadaAbstract:Abstract High-field magnetization was measured for typical itinerant-electron metamagnets Lu(Co 1− x Ga x ) 2 with x =0.06 and 0.07 at temperatures from 4.2 to 300 K in pulsed magnetic fields up to 45 T . Landau coefficients A ( T ), B ( T ) and C ( T ) were determined by fitting measured M – H curves to the equation, H = A ( T ) M + B ( T ) M 3 + C ( T ) M 5 . The temperature dependence of the Landau coefficients was well explained by the theory of the metamagnetic transition considering the Magnetovolume Effect.
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giant Magnetovolume Effect of crte
Journal of Alloys and Compounds, 2000Co-Authors: T Kanomata, K Kamishima, T Kaneko, Aruga H Katori, Y Sugawara, T GotoAbstract:Abstract The pressure change of the spontaneous magnetization σ S of the itinerant electron ferromagnet CrTe has been determined in the ranges of hydrostatic pressure and temperature of 0–6.1 kbar and 4.2–70 K, respectively. The spontaneous magnetization decreases linearly with pressure at temperatures from 4.2 to 70 K. The values of d σ S /d p and d ln σ S /d p at 4.2 K are found to be −0.92 emu g −1 kbar −1 and −1.2×10 −2 kbar −1 , respectively.
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Magnetovolume Effect of srruo3
Journal of The Magnetics Society of Japan, 1999Co-Authors: T Kanomata, K Kamishima, T Goto, H Yoshida, T Kaneko, N Suzuki, H Fujimori, H Kawanaka, Y NishiharaAbstract:The magnetic properties of an itinerant ferromagnet SrRuO3 have been determined in the hydrostatic pressure, temperature and magnetic field range 0-13.2 kbar, 4.2-300 K, and 0-90 kOe, respectively. The pressure derivatives of the Curie temperature and saturation magnetization at 4.2 K are found to be -0.67 K/kbar and -0.47 emu/g kbar, respectively
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Magnetovolume Effect of la0 7sr0 3mno3
The Review of High Pressure Science and Technology, 1998Co-Authors: T Kanomata, K Kamishima, T Goto, H Yoshida, N Suzuki, T KanekoAbstract:The magnetization curves at 4. 2 K of La0. 7Sr0. 3MnO3 are obtained under hydrostatic pressure up to 10. 1 kbar by employing subtraction magnetometer. The saturation magnetization σg at 4. 2 K increases with applied pressure and the pressure dependence of σg is nonlinear. Furthermore, the pressure derivative of the Curie temperature (Tc) of La0. 7Sr0. 3MnO3 is obtained from the result of measurement of temperature dependence of initial permeability at various pressures. The value of dTc/dp is found to be +0. 13 K/kbar.
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Magnetovolume Effect of co2b
Journal of Alloys and Compounds, 1997Co-Authors: T Kanomata, N Kumagai, A Haga, K Kamishima, T Goto, Hisamichi Kimura, H Yoshida, T Kaneko, Akihisa InoueAbstract:Abstract The Effect of pressure on the Curie temperature Tc and the saturation magnetization σ at 4.2 K for Co2B are investigated. Tc decreases linearly with pressure. The value of ∂T c ∂p is −1.1 K kbar−1. The spontaneous magnetization at 4.2 K is independent of pressure. Furthermore, a positive spontaneous magnetostriction is observed only for the lattice parameter c.
S S Jaswal - One of the best experts on this subject based on the ideXlab platform.
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Magnetovolume Effect in fe rich rare earth compounds nd5fe17h16
Journal of Magnetism and Magnetic Materials, 2001Co-Authors: R F Sabiryanov, S S JaswalAbstract:Abstract Curie temperatures ( T c ) of Fe-rich rare-earth compounds are very sensitive to the changes in the hybridization. This is responsible for the well-known large increase in T c of 2–17 compounds with interstitial and substitutional modifications. The Nd 5 Fe 17 compound has attracted some attention recently as a possible permanent-magnet material. Hydrogenation of this compound (Nd 5 Fe 17 H 16 ) produces 14.4% volume expansion and increases its T c and magnetization by 14% and 20%, respectively. Because of the large number of atom per unit cell in this crystal (264 atoms) and the lack of information on the positions of hydrogen atoms, we perform first-principle electronic structure calculations for different volumes to study the Effect of interstitial impurities such as H on the magnetic properties of Nd 5 Fe 17 This is a resonable procedure because the primariy Effect of minimally hybridizing impurity such as H is the Magnetovolume Effect. Because of the similar close-packed environment in Fe-rich compounds and fcc iron these calculations are repeated for fcc iron and the varition of T c with the average Wigner–Seitz radius is quite similar for the two systems giving a universal curve for Fe-rich compounds. The calculated results are also in good agreement with the experimental data for Nd 5 Fe 17 H 16 .
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Magnetovolume Effect in nd sub 5 fe sub 17
Journal of Applied Physics, 2000Co-Authors: R F Sabiryanov, S S JaswalAbstract:The Effect of volume expansion on the magnetic properties of Nd{sub 5}Fe{sub 17} is explored using first-principle electronic structure calculations. A volume expansion of 6% increases the magnetization by {approx}6% and the average total exchange parameter by {approx}34%. As a result, the Curie temperature (T{sub C}) is expected to increase from 509 to 682 K. Therefore, some nonhybridizing interstitial and substitutional impurities should produce a moderate increase in T{sub C} of Nd{sub 5}Fe{sub 17}. The possible interstitial sites are discussed. (c) 2000 American Institute of Physics.
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Magnetovolume Effect in nd5fe17
Journal of Applied Physics, 2000Co-Authors: R F Sabiryanov, S S JaswalAbstract:The Effect of volume expansion on the magnetic properties of Nd5Fe17 is explored using first-principle electronic structure calculations. A volume expansion of 6% increases the magnetization by ∼6% and the average total exchange parameter by ∼34%. As a result, the Curie temperature (TC) is expected to increase from 509 to 682 K. Therefore, some nonhybridizing interstitial and substitutional impurities should produce a moderate increase in TC of Nd5Fe17. The possible interstitial sites are discussed.
Baogen Shen - One of the best experts on this subject based on the ideXlab platform.
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Magnetovolume Effect in intermetallics lafe13 xsix
Journal of Physics: Condensed Matter, 2006Co-Authors: Huaiwu Zhang, Fengxia Hu, Chuang Dong, Baogen ShenAbstract:Based on the Bean–Rodbell model, which assumes a linear variation of exchange coupling with atom spacing, the Magnetovolume Effects in LaFe13−xSix (x = 1.2–2.0) have been systematically studied. A relation between phase volume and magnetization is first obtained by comparing the structural and magnetic data collected at various temperatures. The maximum spontaneous magnetostriction thus derived is dependent on the content of Si, linearly decreasing from ~2.15% for x = 1.2 to ~1.12% for x = 2. Based on these results and limited experimental data, the parameters involved in the Bean–Rodbell model are determined for the LaFe13−xSix compounds. Further analysis indicates that the Bean–Rodbell model equipped with these parameters gives a satisfactory description of the Magnetovolume Effects produced by interstitial hydrogen for the LaFe11.44Si1.56 hydride. To explain the pressure Effects, in contrast, changes of the parameters under pressure, which are a result of the enhancement of the first-order character of the phase transition, have to be taken into account. These results indicate that either the increase or the decrease of the Curie temperature is simply a consequence of the variation of the phase volume due to the introduction of interstitial atoms or the application of a high pressure, and can be described well by the Bean–Rodbell model.
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Magnetovolume Effect in intermetallics LaFe13−xSix
Journal of Physics: Condensed Matter, 2006Co-Authors: Huaiwu Zhang, Fengxia Hu, Chuang Dong, Baogen ShenAbstract:Based on the Bean–Rodbell model, which assumes a linear variation of exchange coupling with atom spacing, the Magnetovolume Effects in LaFe13−xSix (x = 1.2–2.0) have been systematically studied. A relation between phase volume and magnetization is first obtained by comparing the structural and magnetic data collected at various temperatures. The maximum spontaneous magnetostriction thus derived is dependent on the content of Si, linearly decreasing from ~2.15% for x = 1.2 to ~1.12% for x = 2. Based on these results and limited experimental data, the parameters involved in the Bean–Rodbell model are determined for the LaFe13−xSix compounds. Further analysis indicates that the Bean–Rodbell model equipped with these parameters gives a satisfactory description of the Magnetovolume Effects produced by interstitial hydrogen for the LaFe11.44Si1.56 hydride. To explain the pressure Effects, in contrast, changes of the parameters under pressure, which are a result of the enhancement of the first-order character of the phase transition, have to be taken into account. These results indicate that either the increase or the decrease of the Curie temperature is simply a consequence of the variation of the phase volume due to the introduction of interstitial atoms or the application of a high pressure, and can be described well by the Bean–Rodbell model.
I V Svechkarev - One of the best experts on this subject based on the ideXlab platform.
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Magnetovolume Effect in Ce(Ni{1-x}Cu{x})5 alloys
arXiv: Strongly Correlated Electrons, 2006Co-Authors: G E Grechnev, A S Panfilov, I V Svechkarev, A V Logosha, O Musil, P SvobodaAbstract:Magnetic susceptibility of the isostructural Ce(Ni{1-x}Cu{x})5 alloys (0< x
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Magnetovolume Effect in ce ni 1 x cu x 5 alloys
arXiv: Strongly Correlated Electrons, 2006Co-Authors: G E Grechnev, A S Panfilov, I V Svechkarev, A V Logosha, O Musil, P SvobodaAbstract:Magnetic susceptibility of the isostructural Ce(Ni{1-x}Cu{x})5 alloys (0< x <0.9) was studied as a function of the hydrostatic pressure up to 2 kbar at fixed temperatures 77.3 and 300 K, using a pendulum-type magnetometer. A pronounced magnitude of the pressure Effect is found to be negative in sign and to depend strongly and non-monotonously on the Cu content, showing a sharp maximum in vicinity of x = 0.4. The experimental results are discussed in terms of the Ce valence change under pressure. It has been concluded that the fractional occupation of the f-states, which corresponds to the half-integer valence of Ce ion (3.5), is favorable for the valence instability in alloys studied. For the reference CeNi5 compound the main contributions to magnetic susceptibility and their volume dependence are calculated ab initio within the local spin density approximation (LSDA), and appeared to be in close agreement with experimental data.
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Magnetovolume Effect in uga3
Journal of Magnetism and Magnetic Materials, 1999Co-Authors: G E Grechnev, A S Panfilov, I V Svechkarev, Anna Delin, B Johansson, J M Wills, Olle ErikssonAbstract:Abstract The magnetic susceptibility χ of the itinerant antiferromagnetic compound UGa 3 has been studied experimentally under pressure up to 2 kbar in the temperature range 64–300 K. This study reveals a pronounced pressure Effect on magnetic properties of UGa 3 and the measured pressure derivative of the Neel temperature is found to be d T N / d P=−1.1 K/kbar. In order to analyze the experimental Magnetovolume Effect, to be specific d ln χ /d ln V , the volume dependent electronic structure of UGa 3 has been calculated ab initio in the paramagnetic phase by employing a relativistic full-potential LMTO method. The Effect of the external magnetic field was included self-consistently by means of the Zeeman operator, as well as orbital polarization. The calculations have brought out a predominance of itinerant uranium 5f states at the Fermi energy, as well as large and competing orbital and spin contributions to χ . The calculated field-induced magnetic moment of UGa 3 and its volume derivative compare favorably with our experimental results.
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Magnetovolume Effect in paramagnetic alloys of cein3 xsnx
Journal of Magnetism and Magnetic Materials, 1996Co-Authors: G E Grechnev, A S Panfilov, N V Savchenko, I V Svechkarev, A Czopnik, A HackemerAbstract:Abstract The Effect of pressure up to 2 kbar on the magnetic susceptibility of CeIn 3- x Sn x alloys, exhibiting a transition from Kondo to the intermediate valence state, was studied at 77.5, 150 and 300 K. The obtained Magnetovolume Effect value, dln χ/dln V , is well above those observed for similar compounds with stable valence. The experimental data have been analyzed assuming a dominant role of changes in the spin fluctuation temperature, T SF , and the band structure under pressure.
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Pressure Effect on the itinerant magnetism of MnSi and FeSi
Journal of Magnetism and Magnetic Materials, 1996Co-Authors: G E Grechnev, A S Panfilov, I V SvechkarevAbstract:Abstract The pressure Effect on the magnetic susceptibility of MnSi and FeSi is studied in the temperature range 78–300 K. The obtained values of the Magnetovolume Effect in the paramagnetic phase of the monosilicides, and the results of detailed LMTO calculations of density of states at the Fermi level as a function of the lattice constant and temperature, were used to evaluate the volume derivatives of the electron-electron interaction parameter in MnSi and the energy gap in FeSi. The role of spin fluctuations in the Magnetovolume Effect is discussed.