We combine effective medium theory(EMT) with the two-channel conducting model to study the magnetic granular concentration dependence of a giant magnetoresistance(GMR) in magnetic granular composites.The composite is ...We combine effective medium theory(EMT) with the two-channel conducting model to study the magnetic granular concentration dependence of a giant magnetoresistance(GMR) in magnetic granular composites.The composite is composed of small magnetic granules (such as Co) embedded in an immiscible nonmagnetic metallic matrix (such as Ag).We consider the influence of granule size and concentration respectively.Firstly,granules have a distribution in size,resulting in superparamagnetic(SPM) granules and ferromagnetic granules which have different contributions to conductance.Secondly,the effective surface scattering is changed with the changes of concentration.The calculated result of GMR is in agreement with theexperimental data.展开更多
The phase diagrams and the other crtical properties of S-3/2 Ising model in random longitudinal and transverse fields(RLIM) are dicussed with the approximate scheme combined by mean-field renormalization group theory(...The phase diagrams and the other crtical properties of S-3/2 Ising model in random longitudinal and transverse fields(RLIM) are dicussed with the approximate scheme combined by mean-field renormalization group theory(MFRG) and the discretized path-integral representation(DPIR).展开更多
A mean-field approximation (MFA) is used to treat the crystal-field and transverse-field effects of the spin-1 Ising modle in the presence of longitudinal field. In spite of its simplicity, this scheme still gives the...A mean-field approximation (MFA) is used to treat the crystal-field and transverse-field effects of the spin-1 Ising modle in the presence of longitudinal field. In spite of its simplicity, this scheme still gives the satisfied results.展开更多
A effective approximate scheme which is combined by cluster with the discrelized path-integral representation (DPIR) is used in the study on the random-bond Ising model in a transverse field (RTIM). The critical therm...A effective approximate scheme which is combined by cluster with the discrelized path-integral representation (DPIR) is used in the study on the random-bond Ising model in a transverse field (RTIM). The critical thermodynamical properties, such as the critical temperature, the critical transverse field, the average magnetization ,the susceptibility and the special heat atc.. are calculated, And some results have been improved.展开更多
A new approximate scheme which is combined by the mean-field renormalization group theory(MFRG) with the discretized path-integral renormalization (DPIR) is employed in the study of the disordered tranverse Ising mode...A new approximate scheme which is combined by the mean-field renormalization group theory(MFRG) with the discretized path-integral renormalization (DPIR) is employed in the study of the disordered tranverse Ising model(TIM).The criticol properties of random-bonds Ising systems on a d-dimensioal lattice are calculated with this new approximate scheme.展开更多
文摘We combine effective medium theory(EMT) with the two-channel conducting model to study the magnetic granular concentration dependence of a giant magnetoresistance(GMR) in magnetic granular composites.The composite is composed of small magnetic granules (such as Co) embedded in an immiscible nonmagnetic metallic matrix (such as Ag).We consider the influence of granule size and concentration respectively.Firstly,granules have a distribution in size,resulting in superparamagnetic(SPM) granules and ferromagnetic granules which have different contributions to conductance.Secondly,the effective surface scattering is changed with the changes of concentration.The calculated result of GMR is in agreement with theexperimental data.
文摘The phase diagrams and the other crtical properties of S-3/2 Ising model in random longitudinal and transverse fields(RLIM) are dicussed with the approximate scheme combined by mean-field renormalization group theory(MFRG) and the discretized path-integral representation(DPIR).
文摘A mean-field approximation (MFA) is used to treat the crystal-field and transverse-field effects of the spin-1 Ising modle in the presence of longitudinal field. In spite of its simplicity, this scheme still gives the satisfied results.
文摘A effective approximate scheme which is combined by cluster with the discrelized path-integral representation (DPIR) is used in the study on the random-bond Ising model in a transverse field (RTIM). The critical thermodynamical properties, such as the critical temperature, the critical transverse field, the average magnetization ,the susceptibility and the special heat atc.. are calculated, And some results have been improved.
文摘A new approximate scheme which is combined by the mean-field renormalization group theory(MFRG) with the discretized path-integral renormalization (DPIR) is employed in the study of the disordered tranverse Ising model(TIM).The criticol properties of random-bonds Ising systems on a d-dimensioal lattice are calculated with this new approximate scheme.
