随机磁场中晶场作用的混合自旋横向伊辛模型的磁化过程
The Magnetization Processes of Mixed Spin Transverse Ising Model with the Crystal Field in a Random Magnetic Field

DOI: 10.12677/CMP.2013.23010, PP. 73-77

Keywords: 磁化过程；混合自旋横向伊辛模型；晶场；随机磁场
Magnetization Processes, Mixed Spin Transverse Ising Model, Crystal Field, Random Magnetic Field

Full-Text   Cite this paper   Add to My Lib

Abstract:

本文在有效场理论框架内，研究随机磁场中晶场作用的混合自旋横向伊辛模型的磁化过程。以二模磁场中混合自旋伊辛模型为基础，分别增大随机浓度、负晶场和横场，以此考察随机磁场、负晶场和横场对磁化过程的影响。随着磁场增大，磁化范围降低。随机浓度和负晶场都能削弱基态的起始磁化简并，不同简并范围之间存在分界线。通过抑制自旋为1子格磁化强度，负晶场还对起始磁化值产生有趣的影响。横场完全打开基态的起始磁化简并。

Within the framework of the effective field theory (EFT), we investigate the magnetization processes of mixed spin-1/2 and spin-1 transverse Ising model with the crystal field in a random magnetic field. Based on the mixed spin Ising model in a bimodal magnetic field, the influences of random magnetic field, the crystal field, and transverse field acting on magnetization process are presented by increasing random concentration, introducing a negative crystal field or transverse field, respectively. As the magnetic field enhancing, the magnetization range reduces. Both random concentration and negative crystal field can weaken the degeneracy of initial magnetization at base state. There exist some demarcation lines between different degeneracy extents. Negative crystal field also affects interestingly the initial magnetization by depressing the sublattice magnetization of spin-1 magnetic atoms. Transverse field opens thoroughly the degeneracy of initial magnetization at zero temperature.

References

[1]	L. L. Gon？alves. Uniaxial anisotropy effects in the Ising model: An exactly soluble model. Physica Scripta, 1985, 32(3): 248- 256.
[2]	T. Kaneyoshi. Curie temperatures and tricritical points in mixed Ising ferromagnetic system. Journal of the Physical Society of Japan, 1987, 56(8): 2675-2680.
[3]	T. Kaneyoshi. A compensation temperature induced by a crystal- field interaction in a ferrimagnetic mixed Ising system. Solid State Communications, 1989, 70(10): 975-977.
[4]	T. Kaneyoshi, E. F. Sarmento and I. P. Fittipaldi. Magnetic properties of amorphous mixed Ising spin systems in a transverse field. Physical Review B, 1988, 38(4): 2649-2658.
[5]	T. Kaneyoshi, E. F. Sarmento and I. P. Fittipaldi. An effective- field theory of mixed Ising spin sys-tems in transverse fields. Physica Status Solidi (b), 1988, 150(1): 261-272.
[6]	S. L. Yan, C. Z. Yang. The compensation temperature study of the mixed Ising ferrimagnetic spin system with crystal field in a transverse field. Zeitschrift für Physik B: Condensed Matter, 1997, 103(1): 93-96.
[7]	N. Benayad, A. Fathi and L. Khaya. Thermody-namical proper- ties of the random field mixed spin Ising model. Physica A, 2001, 300(2): 225-244.
[8]	N. Benayad, A. Fathi and L. Khaya. Thermodynamical proper- ties of the random field mixed spin transverse Ising model. Journal of Magnetism and Magnetic Materials, 2004, 278(3): 407-429.
[9]	Y. F. Zhang, S. L. Yan. The phase dia-grams and compensation behaviors of mixed spin Blume-Capel model in a trimodal mag- netic field. Physics Letters A, 2008, 372(15): 2696-2700.
[10]	R. Honmura, T. Kaneyoshi. Contribution to the new type of effective-field theory of the Ising model. Journal of Physics C: Solid State Physics, 1979, 12(19): 3979-3992.

Full-Text