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Hideki Miyajima - One of the best experts on this subject based on the ideXlab platform.
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Magnetic phase transitions for Body-Centered Tetragonal FeRh1−xPtx system
Journal of Magnetism and Magnetic Materials, 2001Co-Authors: Kaori Takizawa, Teruo Ono, Hideki MiyajimaAbstract:Abstract The magnetic phase transitions near the triple point of FeRh1−xPtx system with Body-Centered Tetragonal structure were studied by means of magnetization measurement and Mossbauer spectroscopy. The composition (x) vs. temperature (T) phase diagram is determined. The triple point exists at x=0.715 and T=388 K. It is noted that the spin fluctuation plays an important role in the magnetic phase transition around the triple point.
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Magnetic properties of martensite in Fe-Ni alloy measured by means of scanning probe microscopy
Journal of Magnetism and Magnetic Materials, 1998Co-Authors: Atsufumi Hirohata, Teruo Ono, Hideki MiyajimaAbstract:Abstract The magnetic domain structure and the surface relief of the martensite in Fe 1- x Ni x alloys were investigated by using both non-contact atomic force microscopy (NC-AFM) and magnetic force microscopy (MFM). The martensite with Body-Centered Tetragonal structure exhibits a large magnetization of 2.0 T.
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Magnetism of Body-Centered Tetragonal FeRh1-xPdx Alloys (I) Magnetic Properties
Journal of the Physical Society of Japan, 1995Co-Authors: Shinji Yuasa, Hideki Miyajima, Yoshichika Otani, Akimasa SakumaAbstract:Crystalline structures and magnetic properties of the FeRh 1- x Pd x system were investigated. Substitution of Pd for Rh stabilized Body-Centered Tetragonal (bct) structure of the ordered CuAu-type with increasing axial ratio c / a from 1.18 to 1.36. The bct alloys in the range x =0.530∼0.61 exhibited a first-order phase transition from antiferromagnetic to ferromagnetic state, while the bct alloys with x
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Magnetism in Body-Centered Tetragonal FeRh1-xPdx Alloys (II) Band Structure
Journal of the Physical Society of Japan, 1995Co-Authors: Akimasa Sakuma, Hideki Miyajima, Shinji Yuasa, Yoshichika OtaniAbstract:First-principle spin-polarized band calculations were performed for the Body-Centered Tetragonal FeRh 1- x Pd x alloys with x =0, 0.5 and 1 as a function of the axial ratio c / a using the LMTO method. The energetically competing ferromagnetic and antiferromagnetic states were found to exist in bcc FeRh and bct FeRh 0.5 Pd 0.5 , as experimentally expected. The substitution of Pd for Rh hardly changes the shape of the density of states but simply raises the Fermi level when the axial ratio is fixed at a constant value. The Tetragonal lattice elongation removes the degeneracy of the Fe d -band, and a large peak of DOS in the minority spin band for the bcc structure splits into two peaks for the bct structure, resulting in a reduction of the Fe magnetic moment. The large Tetragonal elongation in the FeRh 1- x Pd x system is induced by the band Jahn-Teller effect.
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Magneto-Volume and Tetragonal Elongation Effects on Magnetic Phase Transitions of Body-Centered Tetragonal FeRh1-xPtx
Journal of the Physical Society of Japan, 1994Co-Authors: Shinji Yuasa, Hideki Miyajima, Yoshichika OtaniAbstract:Magnetic properties of FeRh 1- x Pt x system with Body-Centered cubic and Body-Centered Tetragonal (bct) structures were studied by means of X-ray diffractometry, magnetometry and Mossbauer spectroscopy, and the phase diagram in a temperature-composition plane was determined. With substituting Pt for Rh, the axial ratio c / a was increased and the bct phase was stabilized. With increasing temperature, the bct alloys with 0.72< x
Akimasa Sakuma - One of the best experts on this subject based on the ideXlab platform.
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degree of order dependence on magnetocrystalline anisotropy in body centered Tetragonal feco alloys
Applied Physics Express, 2012Co-Authors: Yohei Kota, Akimasa SakumaAbstract:We investigate the magnetocrystalline anisotropy (MCA) energy of Tetragonal distorted FeCo alloys depending on the degree of order by first-principles electronic structure calculation combined with the coherent potential approximation. The obtained results indicate that the MCA energy of FeCo alloys strongly depends on the degree of order under optimal conditions, where the axial ratio of the Body-Centered Tetragonal (bct) structure is 1.25 and the composition is Fe0.5Co0.5. We find that the modification of the electronic structure resulting from electron scattering by chemical disorder has a considerable influence on the MCA under these conditions.
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Magnetism of Body-Centered Tetragonal FeRh1-xPdx Alloys (I) Magnetic Properties
Journal of the Physical Society of Japan, 1995Co-Authors: Shinji Yuasa, Hideki Miyajima, Yoshichika Otani, Akimasa SakumaAbstract:Crystalline structures and magnetic properties of the FeRh 1- x Pd x system were investigated. Substitution of Pd for Rh stabilized Body-Centered Tetragonal (bct) structure of the ordered CuAu-type with increasing axial ratio c / a from 1.18 to 1.36. The bct alloys in the range x =0.530∼0.61 exhibited a first-order phase transition from antiferromagnetic to ferromagnetic state, while the bct alloys with x
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Magnetism in Body-Centered Tetragonal FeRh1-xPdx Alloys (II) Band Structure
Journal of the Physical Society of Japan, 1995Co-Authors: Akimasa Sakuma, Hideki Miyajima, Shinji Yuasa, Yoshichika OtaniAbstract:First-principle spin-polarized band calculations were performed for the Body-Centered Tetragonal FeRh 1- x Pd x alloys with x =0, 0.5 and 1 as a function of the axial ratio c / a using the LMTO method. The energetically competing ferromagnetic and antiferromagnetic states were found to exist in bcc FeRh and bct FeRh 0.5 Pd 0.5 , as experimentally expected. The substitution of Pd for Rh hardly changes the shape of the density of states but simply raises the Fermi level when the axial ratio is fixed at a constant value. The Tetragonal lattice elongation removes the degeneracy of the Fe d -band, and a large peak of DOS in the minority spin band for the bcc structure splits into two peaks for the bct structure, resulting in a reduction of the Fe magnetic moment. The large Tetragonal elongation in the FeRh 1- x Pd x system is induced by the band Jahn-Teller effect.
Borje Johansson - One of the best experts on this subject based on the ideXlab platform.
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atomic long range order effects on curie temperature and adiabatic spin wave dynamics in strained fe co alloy films
Physical Review B, 2016Co-Authors: Stephan Schonecker, Borje Johansson, Levente VitosAbstract:The strained Fe-Co alloy in Body-Centered Tetragonal (bct) structure has raised considerable interest due to its giant uniaxial magnetocrystalline anisotropy energy. On the basis of the classical H ...
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Instability of the Body-Centered Tetragonal phase of iron under extreme conditions
Physical Review B, 2009Co-Authors: A. S. Mikhaylushkin, Anatoly B Belonoshko, Borje Johansson, Igor A. Abrikosov, Sergey SimakAbstract:The influence of the Tetragonal and orthorhombic axial distortions on the Body-Centered cubic (bcc) phase of Fe at extreme conditions has been studied by means of first-principles calculations. We ...
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stability of the body centered Tetragonal phase of fe at high pressure ground state energies phonon spectra and molecular dynamics simulations
Physical Review B, 2006Co-Authors: Anatoly B Belonoshko, Eyvaz I Isaev, Natalia V Skorodumova, Borje JohanssonAbstract:It is well established that at a pressure of several megabars and low temperature Fe is stable in the hexagonal-close-packed (hcp) phase. However, there are indications that on heating a high-pressure hcp phase of Fe transforms to a less dense (open structure) phase. Two phases have been suggested as candidates for these high-temperature stable phases: namely, Body-Centered-cubic and Body-Centered-Tetragonal (bct) phases. We performed first-principles molecular dynamics and phonon analysis of the bct Fe phase and demonstrated its dynamical instability. This allows us to dismiss the existence of the bct Fe phase under the high-pressure high-temperature conditions of the Earth's inner core.
Teruo Ono - One of the best experts on this subject based on the ideXlab platform.
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Magnetic phase transitions for Body-Centered Tetragonal FeRh1−xPtx system
Journal of Magnetism and Magnetic Materials, 2001Co-Authors: Kaori Takizawa, Teruo Ono, Hideki MiyajimaAbstract:Abstract The magnetic phase transitions near the triple point of FeRh1−xPtx system with Body-Centered Tetragonal structure were studied by means of magnetization measurement and Mossbauer spectroscopy. The composition (x) vs. temperature (T) phase diagram is determined. The triple point exists at x=0.715 and T=388 K. It is noted that the spin fluctuation plays an important role in the magnetic phase transition around the triple point.
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Magnetic properties of martensite in Fe-Ni alloy measured by means of scanning probe microscopy
Journal of Magnetism and Magnetic Materials, 1998Co-Authors: Atsufumi Hirohata, Teruo Ono, Hideki MiyajimaAbstract:Abstract The magnetic domain structure and the surface relief of the martensite in Fe 1- x Ni x alloys were investigated by using both non-contact atomic force microscopy (NC-AFM) and magnetic force microscopy (MFM). The martensite with Body-Centered Tetragonal structure exhibits a large magnetization of 2.0 T.
Levente Vitos - One of the best experts on this subject based on the ideXlab platform.
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atomic long range order effects on curie temperature and adiabatic spin wave dynamics in strained fe co alloy films
Physical Review B, 2016Co-Authors: Stephan Schonecker, Borje Johansson, Levente VitosAbstract:The strained Fe-Co alloy in Body-Centered Tetragonal (bct) structure has raised considerable interest due to its giant uniaxial magnetocrystalline anisotropy energy. On the basis of the classical H ...