CAJ | 학술논문

基于伊辛模型的单自旋反转蒙特卡洛算法，考虑了粒子间的最近邻以及次近邻相互作用，研究了无序Fe0.5 Mn0.1 Al0.4合金的磁化强度和磁熵变.首先，强调了粒子间的次近邻相关作用对体系的磁性和热力学性质的影响，明确了次近邻相互作用系数，证实了低温合金阻挫的存在；其次，研究了在相变温度处（不同磁场下）磁化强度随外加磁场（温度）的变化情况以及磁性粒子对磁化强度的贡献，发现反铁磁性粒子Mn在低温区对Fe0.5 Mn0.1 Al0.4合金的相变起了主要作用，而高温区体系的相变是由铁磁性粒子Fe贡献的；最后，分析了体系在相变温度处磁熵变数值随外加磁场的变化情况以及磁熵变在不同的外磁场下随温度的变化情况，当外加磁场H＝0.14（a.u.）时，Mn粒子在冻结温度处的平均磁化强度为零，体系处于最无序的状态，对应的磁熵变ΔS（0.1，0.14）达到了正向最大值，极值的位置对应于体系的相变温度.
기우이신모형적단자선반전몽특잡락산법，고필료입자간적최근린이급차근린상호작용，연구료무서Fe0.5 Mn0.1 Al0.4합금적자화강도화자적변.수선，강조료입자간적차근린상관작용대체계적자성화열역학성질적영향，명학료차근린상호작용계수，증실료저온합금조좌적존재；기차，연구료재상변온도처（불동자장하）자화강도수외가자장（온도）적변화정황이급자성입자대자화강도적공헌，발현반철자성입자Mn재저온구대Fe0.5 Mn0.1 Al0.4합금적상변기료주요작용，이고온구체계적상변시유철자성입자Fe공헌적；최후，분석료체계재상변온도처자적변수치수외가자장적변화정황이급자적변재불동적외자장하수온도적변화정황，당외가자장H＝0.14（a.u.）시，Mn입자재동결온도처적평균자화강도위령，체계처우최무서적상태，대응적자적변ΔS（0.1，0.14）체도료정향최대치，겁치적위치대응우체계적상변온도.
By means of single spin flip Metropolis dynamics on the basis of a random site-diluted three-dimen-sional Ising model with nearest-neighbor interactions and next-nearest-neighbor interactions, the magnetiza-tion and magnetic entropy change of Fe0.5 Mn0.1 Al0.4 alloy are researched.Firstly, the influence of next-nearest-neighbor interactions on magnetic and thermodynamic properties of the system is emphasized, from which next-nearest-neighbor interaction coefficient is determined, and the existence of frustration in the low temperature is also confirmed.Secondly, In the phase transition temperature magnetization as a function of magnetic field or under different magnetic field magnetization as a function of temperature and contribution of magnetic particles to the magnetization are studied, we conclusively demonstrate that the antiferromagnetic Mn particle plays a crucial role in determining low-temperature phase transition, whereas the high-temperature phase transition is contrib-uted mainly by Fe component.Finally, the external magnetic field dependence of magnetic entropy change is an-alyzed on the phase transition temperature, the magnetization of the antiferromagnetic Mn particle is zero on freezing temperature when external magnetic field is 0.14 a.u., which shows the system is the most disorder con-dition and the corresponding magnetic entropy changeΔS (0.1,0.14) reaches a positive maximum value.Fur-thermore, from magnetic entropy change as a function of temperature curve under different magnetic fields, one can determine the phase transition temperature of system.