The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
T. Goto - One of the best experts on this subject based on the ideXlab platform.
-
Giant magnetocaloric effect in itinerant-electron metamagnets
Physica B-condensed Matter, 2004Co-Authors: H Yamada, T. GotoAbstract:Abstract Based on the theory of the itinerant-electron Metamagnetism, an isothermal magnetic entropy change is discussed for 3d transition metal compounds. The magnetic entropy change depends not only on the magnetization jump at the Curie temperature, but also on the temperature dependence of the critical field of the metamagnetic transition. The isothermal magnetic entropy changes for Co(S,Se) 2 , Lu(Co,Al) 2 and Lu(Co,Ga) 2 are estimated and compared with those observed for MnFe(P,As) and La(Fe,Si) 13 .
-
Physics of anisotropic itinerant 5f-electron Metamagnetism in UCo1−xTxAl (T=Fe, Ni)
Journal of Magnetism and Magnetic Materials, 2004Co-Authors: N.v. Mushnikov, T. Goto, H. Yamada, Alexander V. Andreev, Vladimír SechovskýAbstract:Abstract UCoAl is an itinerant 5f-electron metamagnet with a strong uniaxial anisotropy. We studied the magnetization of the UCo 1− x T x Al (T=Fe, Ni) single crystals as a function of magnetic field (0–9 T), temperature (1.5–40 K) and external pressure (0–1.2 GPa). The Ni substitution for Co yields an increase of the critical field of Metamagnetism. Contrary, just 2% substitution of Fe for Co in UCoAl stabilizes ferromagnetic ground state, while the reentrant Metamagnetism is observed in substitution-induced ferromagnets under pressure. Experimental data have been analyzed within the theory of itinerant electron Metamagnetism considering anisotropic thermal fluctuations of magnetic moment.
-
decoupling of the magnetic ordering of the rare earth and the co sublattice in er 1 x y x co 2 compounds driven by substitution or pressure
Physical Review B, 2000Co-Authors: R Hauser, A. S. Markosyan, K. Kamishima, E. Bauer, E Gratz, H Muller, M Rotter, H Michor, G Hilscher, T. GotoAbstract:The thermodynamic and transport properties of the ${\mathrm{Er}}_{1\ensuremath{-}x}{\mathrm{Y}}_{x}{\mathrm{Co}}_{2}$ system were studied in the concentration range $0.0l~xl~1.0.$ In this system, the first-order magnetic phase transition observed in ${\mathrm{ErCo}}_{2}$ at ${T}_{\mathrm{C}}=32$ K is related to the itinerant electron Metamagnetism of the d subsystem (Co sublattice) driven by the onset of magnetic ordering within the Er sublattice. By employing magnetic, specific heat, thermal expansion, and resistivity measurements we show that in a limited concentration range ${x}_{{\mathrm{cr}}^{\ensuremath{'}}}lxl{x}_{\mathrm{cr}}$ and pressure ${P}_{{\mathrm{cr}}^{\ensuremath{'}}}lPl{P}_{\mathrm{cr}}$ the itinerant Co sublattice orders magnetically at ${T}_{\mathrm{C}}^{\mathrm{Co}},$ which is lower than ${T}_{\mathrm{C}}^{R}$ of the Er sublattice. This is referred either to a weakening of the effective molecular field acting on the Co sites owing to the yttrium subsititution or to a pressure-driven increase of the critical field necessary to induce a magnetic moment on the Co sites. On further increasing the yttrium concentration or the pressure only the Er sublattice exhibits long-range order. The theoretical calculations within the molecular field approximation are in agreement with the experimental magnetic x-$T$ phase diagram of the ${\mathrm{Er}}_{1\ensuremath{-}x}{\mathrm{Y}}_{x}{\mathrm{Co}}_{2}$ system and confirm the effect of a separate ordering of the magnetic sublattices with reasonable parameters used for the intrasublattice Er-Er and intersublattice Er-Co exchange interactions. A field-induced collapse of the Co moment, inverse itinerant electron Metamagnetism, is well observable by magnetoresistance measurements at appropriate values of concentration and external pressure. The existence of itinerant electron Metamagnetism in the Co sublattice is found to be limited in temperature by ${T}_{0},$ a characteristic temperature which is sensitive to substitution and pressure.
-
Effects of external pressure on the 5f-band Metamagnetism in UCoAl
Physical Review B, 1997Co-Authors: Alexander V. Andreev, T. Goto, M.i. Bartashevich, K. Kamishima, Ladislav Havela, Vladimír SechovskýAbstract:UCoAl exhibits below 16 K anisotropic 5f-band Metamagnetism induced by magnetic fields as low as \ensuremath{\sim}1 T applied along the c axis of the hexagonal structure. No metamagnetic transition is observed in fields up to 40 T applied within the basal plane. The critical field of the metamagnetic transition ${\mathrm{B}}_{\mathrm{c}}$ is composition dependent within the homogeneity range. The metamagnetic transition is found to be very sensitive to external pressure. The value of ${\mathrm{B}}_{\mathrm{c}}$ increases with the rate ${\mathrm{dB}}_{\mathrm{c}}$ /dp=0.27 T/kbar, whereas the magnetization gained through the transition becomes reduced. The critical pressure of 24 kbar (corresponding to \ensuremath{\sim}2% volume contraction) for disappearance of Metamagnetism in UCoAl has been estimated. Relations of UCoAl to 3d-band metamagnets are discussed.
-
5f-band Metamagnetism in UCoAl
Physica B-condensed Matter, 1997Co-Authors: Ladislav Havela, T. Goto, Alexander V. Andreev, Vladimír Sechovský, M.i. Bartashevich, I.k Kozlovskaya, K. Prokes, Pavel Javorský, K. KamishimaAbstract:UCoAl is a 5f-band metamagnet characterized by a very low critical field Bc ≈ 0.8 T, which induces magnetization of 0.3 μB/f.u. by a distinct transition. Bc increases with increasing temperature with the rate consistent with the reduced γ-coefficient in the high-field state. Bc-values are also sensitive to stoichiometry and external pressure.
R. S. Perry - One of the best experts on this subject based on the ideXlab platform.
-
Investigation into the Itinerant Metamagnetism of Sr3Ru2O7 for the Field Parallel to the Ruthenium Oxygen Planes
Journal of the Physical Society of Japan, 2005Co-Authors: R. S. Perry, Takashi Tayama, Kentaro Kitagawa, Toshiro Sakakibara, Kenji Ishida, Yoshiteru MaenoAbstract:We report a detailed investigation into the Metamagnetism of Sr 3 Ru 2 O 7 at low temperatures for the magnetic field parallel to the ruthenium oxygen planes. The Metamagnetism is studied as a func...
-
investigation into the itinerant Metamagnetism of sr3ru2o7 for the field parallel to the ruthenium oxygen planes
arXiv: Strongly Correlated Electrons, 2004Co-Authors: R. S. Perry, Takashi Tayama, Kentaro Kitagawa, Toshiro Sakakibara, Kenji Ishida, Yoshiteru MaenoAbstract:We report a detailed investigation into the Metamagnetism of Sr3Ru2O7 at low temperatures for the magnetic field parallel to the ruthenium oxygen planes. The Metamagnetism is studied as a function of temperature, magnetic field and sample quality using magnetisation, magnetotransport and specific heat as probes. From hysteretic behaviour in the magnetisation, we confirm earlier work and observe a finite temperature critical point at (5 T, >0.25 K). In our highest quality samples two-step metamagnetic transitions are additionally observed at 5.8 T and at 6.3 T, which coincide with a range of broad maximum in the magnetoresistance. At low temperatures, these two metamagnetic features each further split in two. Such behaviour of the multiple transitions are qualitatively different from the first order transition at 5.1 T.
-
Metamagnetism and critical fluctuations in high quality single crystals of the bilayer ruthenate sr3ru2o7
Physical Review Letters, 2001Co-Authors: R. S. Perry, L M Galvin, S A Grigera, L Capogna, A J Schofield, A P Mackenzie, May Chiao, S R Julian, Shinichi Ikeda, Satoru NakatsujiAbstract:We report the results of low temperature transport, specific heat, and magnetization measurements on high quality single crystals of the bilayer perovskite ${\mathrm{Sr}}_{3}{\mathrm{Ru}}_{2}{\mathrm{O}}_{7}$, which is a close relative of the unconventional superconductor ${\mathrm{Sr}}_{2}{\mathrm{RuO}}_{4}$. Metamagnetism is observed, and transport and thermodynamic evidence for associated critical fluctuations is presented. These relatively unusual fluctuations might be pictured as variations in the Fermi surface topography itself.
Vladimír Sechovský - One of the best experts on this subject based on the ideXlab platform.
-
Transition from Ferromagnetism to Metamagnetism under Pressure in a U0.94Y0.06CoAl Single Crystal
Journal of the Physical Society of Japan, 2007Co-Authors: Alexander V. Andreev, N.v. Mushnikov, Vladimír Sechovský, Keiichi Koyama, Yoshinobu Shiokawa, Isamu Satoh, Kazuo WatanabeAbstract:Substitution of Y for U in the itinerant 5f-electron metamagnet UCoAl transforms the system to a ferromagnetic ground state. Application of external hydrostatic pressure above 0.3 GPa suppresses the ferromagnetism and restores the “UCoAl-type” Metamagnetism. However, the metamagnetic transition becomes of the second-order type instead of the first-order one for the parent UCoAl.
-
Physics of anisotropic itinerant 5f-electron Metamagnetism in UCo1−xTxAl (T=Fe, Ni)
Journal of Magnetism and Magnetic Materials, 2004Co-Authors: N.v. Mushnikov, T. Goto, H. Yamada, Alexander V. Andreev, Vladimír SechovskýAbstract:Abstract UCoAl is an itinerant 5f-electron metamagnet with a strong uniaxial anisotropy. We studied the magnetization of the UCo 1− x T x Al (T=Fe, Ni) single crystals as a function of magnetic field (0–9 T), temperature (1.5–40 K) and external pressure (0–1.2 GPa). The Ni substitution for Co yields an increase of the critical field of Metamagnetism. Contrary, just 2% substitution of Fe for Co in UCoAl stabilizes ferromagnetic ground state, while the reentrant Metamagnetism is observed in substitution-induced ferromagnets under pressure. Experimental data have been analyzed within the theory of itinerant electron Metamagnetism considering anisotropic thermal fluctuations of magnetic moment.
-
Metamagnetism of UCoAl under high pressure
Physica B-condensed Matter, 2000Co-Authors: Tsuneaki Goto, N.v. Mushnikov, Alexander V. Andreev, H Yamada, Vladimír SechovskýAbstract:Abstract The susceptibility and magnetization of metamagnetic UCoAl were measured under high pressures up to 1.2 GPa. The metamagnetic behavior under high pressure is very similar to that of a typical 3d itinerant metamagnet.
-
Effects of external pressure on the 5f-band Metamagnetism in UCoAl
Physical Review B, 1997Co-Authors: Alexander V. Andreev, T. Goto, M.i. Bartashevich, K. Kamishima, Ladislav Havela, Vladimír SechovskýAbstract:UCoAl exhibits below 16 K anisotropic 5f-band Metamagnetism induced by magnetic fields as low as \ensuremath{\sim}1 T applied along the c axis of the hexagonal structure. No metamagnetic transition is observed in fields up to 40 T applied within the basal plane. The critical field of the metamagnetic transition ${\mathrm{B}}_{\mathrm{c}}$ is composition dependent within the homogeneity range. The metamagnetic transition is found to be very sensitive to external pressure. The value of ${\mathrm{B}}_{\mathrm{c}}$ increases with the rate ${\mathrm{dB}}_{\mathrm{c}}$ /dp=0.27 T/kbar, whereas the magnetization gained through the transition becomes reduced. The critical pressure of 24 kbar (corresponding to \ensuremath{\sim}2% volume contraction) for disappearance of Metamagnetism in UCoAl has been estimated. Relations of UCoAl to 3d-band metamagnets are discussed.
-
5f-band Metamagnetism in UCoAl
Physica B-condensed Matter, 1997Co-Authors: Ladislav Havela, T. Goto, Alexander V. Andreev, Vladimír Sechovský, M.i. Bartashevich, I.k Kozlovskaya, K. Prokes, Pavel Javorský, K. KamishimaAbstract:UCoAl is a 5f-band metamagnet characterized by a very low critical field Bc ≈ 0.8 T, which induces magnetization of 0.3 μB/f.u. by a distinct transition. Bc increases with increasing temperature with the rate consistent with the reduced γ-coefficient in the high-field state. Bc-values are also sensitive to stoichiometry and external pressure.
Chang Seop Hong - One of the best experts on this subject based on the ideXlab platform.
-
one dimensional cyanide bridged mniiiwv bimetallic complexes Metamagnetism spontaneous resolution and slow magnetic relaxation
Inorganic Chemistry, 2009Co-Authors: Seok Woo Choi, Jung Hee Yoon, Hyoung Chan Kim, Dae Won Ryu, Jin Wuk Lee, Hyosug Lee, B K Cho, Chang Seop HongAbstract:The reaction of [W(CN)6(bpy)]− with the corresponding Mn Schiff bases led to the formation of two antiferromagnetic (1) and ferromagnetic (2) chains. The formation of the conglomerate (2) is associated with chiral induction by the enantiomeric chelate-ring conformation of the Mn Schiff base. Modulation of the linking groups in the Mn Schiff bases affects the interchain contacts, causing alteration of the magnetic behaviors from Metamagnetism (1) to slow magnetic relaxation (2).
-
cyanide bridged wv coii double zigzag chain based on an octacoordinated w precursor Metamagnetism and spin canting
Inorganic Chemistry, 2007Co-Authors: Jung Hee Yoon, Jeong Hak Lim, Seok Woo Choi, Hyoung Chan Kim, Chang Seop HongAbstract:A cyanide-bridged W−Co bimetallic complex (1) with a double-zigzag chain structure was characterized in terms of structure and magnetism. Compound 1 exhibits Metamagnetism and spin canting induced by the presence of anisotropic CoII ions and noncovalent interactions.
-
coexistence of spin canting and Metamagnetism in a one dimensional mn iii complex bridged by a single end to end azide
Inorganic Chemistry, 2006Co-Authors: Jeong Hak Lim, Hyoung Chan Kim, Chang Seop HongAbstract:Two manganese(III) azide complexes capped with tetradentate Schiff bases were characterized structurally and magnetically. The replacement of halogens on the Schiff bases leads to a drastic structural alteration from a dimer (1) bridged by phenoxide to a one-dimensional chain (2) linked by azide in a single end-to-end mode. Notably, magnetic studies of 2 show the concomitant existence of spin canting and Metamagnetism.
Alexander V. Andreev - One of the best experts on this subject based on the ideXlab platform.
-
Transition from Ferromagnetism to Metamagnetism under Pressure in a U0.94Y0.06CoAl Single Crystal
Journal of the Physical Society of Japan, 2007Co-Authors: Alexander V. Andreev, N.v. Mushnikov, Vladimír Sechovský, Keiichi Koyama, Yoshinobu Shiokawa, Isamu Satoh, Kazuo WatanabeAbstract:Substitution of Y for U in the itinerant 5f-electron metamagnet UCoAl transforms the system to a ferromagnetic ground state. Application of external hydrostatic pressure above 0.3 GPa suppresses the ferromagnetism and restores the “UCoAl-type” Metamagnetism. However, the metamagnetic transition becomes of the second-order type instead of the first-order one for the parent UCoAl.
-
Physics of anisotropic itinerant 5f-electron Metamagnetism in UCo1−xTxAl (T=Fe, Ni)
Journal of Magnetism and Magnetic Materials, 2004Co-Authors: N.v. Mushnikov, T. Goto, H. Yamada, Alexander V. Andreev, Vladimír SechovskýAbstract:Abstract UCoAl is an itinerant 5f-electron metamagnet with a strong uniaxial anisotropy. We studied the magnetization of the UCo 1− x T x Al (T=Fe, Ni) single crystals as a function of magnetic field (0–9 T), temperature (1.5–40 K) and external pressure (0–1.2 GPa). The Ni substitution for Co yields an increase of the critical field of Metamagnetism. Contrary, just 2% substitution of Fe for Co in UCoAl stabilizes ferromagnetic ground state, while the reentrant Metamagnetism is observed in substitution-induced ferromagnets under pressure. Experimental data have been analyzed within the theory of itinerant electron Metamagnetism considering anisotropic thermal fluctuations of magnetic moment.
-
Metamagnetism of UCoAl under high pressure
Physica B-condensed Matter, 2000Co-Authors: Tsuneaki Goto, N.v. Mushnikov, Alexander V. Andreev, H Yamada, Vladimír SechovskýAbstract:Abstract The susceptibility and magnetization of metamagnetic UCoAl were measured under high pressures up to 1.2 GPa. The metamagnetic behavior under high pressure is very similar to that of a typical 3d itinerant metamagnet.
-
Effects of external pressure on the 5f-band Metamagnetism in UCoAl
Physical Review B, 1997Co-Authors: Alexander V. Andreev, T. Goto, M.i. Bartashevich, K. Kamishima, Ladislav Havela, Vladimír SechovskýAbstract:UCoAl exhibits below 16 K anisotropic 5f-band Metamagnetism induced by magnetic fields as low as \ensuremath{\sim}1 T applied along the c axis of the hexagonal structure. No metamagnetic transition is observed in fields up to 40 T applied within the basal plane. The critical field of the metamagnetic transition ${\mathrm{B}}_{\mathrm{c}}$ is composition dependent within the homogeneity range. The metamagnetic transition is found to be very sensitive to external pressure. The value of ${\mathrm{B}}_{\mathrm{c}}$ increases with the rate ${\mathrm{dB}}_{\mathrm{c}}$ /dp=0.27 T/kbar, whereas the magnetization gained through the transition becomes reduced. The critical pressure of 24 kbar (corresponding to \ensuremath{\sim}2% volume contraction) for disappearance of Metamagnetism in UCoAl has been estimated. Relations of UCoAl to 3d-band metamagnets are discussed.
-
5f-band Metamagnetism in UCoAl
Physica B-condensed Matter, 1997Co-Authors: Ladislav Havela, T. Goto, Alexander V. Andreev, Vladimír Sechovský, M.i. Bartashevich, I.k Kozlovskaya, K. Prokes, Pavel Javorský, K. KamishimaAbstract:UCoAl is a 5f-band metamagnet characterized by a very low critical field Bc ≈ 0.8 T, which induces magnetization of 0.3 μB/f.u. by a distinct transition. Bc increases with increasing temperature with the rate consistent with the reduced γ-coefficient in the high-field state. Bc-values are also sensitive to stoichiometry and external pressure.