We present the microscopic origin of the ferromagnetism of Feo.25TaS2 and its finite-temperature magnetic properties.The band structures of Feo.25TaS2 are first obtained by the first-principles calculations and it is ...We present the microscopic origin of the ferromagnetism of Feo.25TaS2 and its finite-temperature magnetic properties.The band structures of Feo.25TaS2 are first obtained by the first-principles calculations and it is found that both conventional and Dirac carriers coexist in metallic Feo.25TaS2-Accordingly,considering the spin-orbit coupling of Fe 3d ion,we derive an effective Ruderman-Kittle-Kasuya-Yosida-type Hamiltonian between Fe spins in the presence of both the conventional parabolic-dispersion and the Dirac linear-dispersion carriers,which contains a Heisenberg-like,an Ising-like and an XY-like term.In addition,we obtain the ferromagnetic Curie temperature Tc by using the cluster self-consistent Held method.Our results could address not only the high ferromagnetic Curie temperature but also the large magnetic anisotropy in Fex TaS2.展开更多
We present a study on the Jahn–Teller(JT)distortions of the TiO_(6),NiO_(6)and MnO_(6)complexes in NaTiO_(2),NaNiO_(2)and NaMnO_(2)triangular compounds with a C_(2)/m structure.The JT vibronic normal modes are found ...We present a study on the Jahn–Teller(JT)distortions of the TiO_(6),NiO_(6)and MnO_(6)complexes in NaTiO_(2),NaNiO_(2)and NaMnO_(2)triangular compounds with a C_(2)/m structure.The JT vibronic normal modes are found to be Q3,Q'4 and Q6 by the group symmetry on the C2/m structure.The magnitude of the normal coordinates(Q3,Q'4,Q6)and the structural parameters of distorted octahedra MO_(6)(M=Ti,Ni,Mn)are obtained and in good agreement with experimental data.The energy level splitting of 3d orbitals and the highest occupied molecular orbital(HOMO)character in the MO_(6)complex are also calculated in accordance with the JT distortions.These results provide a first insight into the groundstate and magnetic properties of distorted triangular compounds AMO_(2).展开更多
基金the National Natural Science Foundation of China under Grant Nos 11774350,11534010 and 11574315.
文摘We present the microscopic origin of the ferromagnetism of Feo.25TaS2 and its finite-temperature magnetic properties.The band structures of Feo.25TaS2 are first obtained by the first-principles calculations and it is found that both conventional and Dirac carriers coexist in metallic Feo.25TaS2-Accordingly,considering the spin-orbit coupling of Fe 3d ion,we derive an effective Ruderman-Kittle-Kasuya-Yosida-type Hamiltonian between Fe spins in the presence of both the conventional parabolic-dispersion and the Dirac linear-dispersion carriers,which contains a Heisenberg-like,an Ising-like and an XY-like term.In addition,we obtain the ferromagnetic Curie temperature Tc by using the cluster self-consistent Held method.Our results could address not only the high ferromagnetic Curie temperature but also the large magnetic anisotropy in Fex TaS2.
基金by the National Natural Science Foundation of China under Grant No 10874186the Knowledge Innovation Project of the Chinese Academy of Sciences.
文摘We present a study on the Jahn–Teller(JT)distortions of the TiO_(6),NiO_(6)and MnO_(6)complexes in NaTiO_(2),NaNiO_(2)and NaMnO_(2)triangular compounds with a C_(2)/m structure.The JT vibronic normal modes are found to be Q3,Q'4 and Q6 by the group symmetry on the C2/m structure.The magnitude of the normal coordinates(Q3,Q'4,Q6)and the structural parameters of distorted octahedra MO_(6)(M=Ti,Ni,Mn)are obtained and in good agreement with experimental data.The energy level splitting of 3d orbitals and the highest occupied molecular orbital(HOMO)character in the MO_(6)complex are also calculated in accordance with the JT distortions.These results provide a first insight into the groundstate and magnetic properties of distorted triangular compounds AMO_(2).
