Possible ground states and parallel magnetic-field-driven phase transitions of collinear antiferromagnets  

作　　者：Hai-Feng Li 

机构地区：[1]Institute of Applied Physics and Materials Engineering,Faculty of Science and Technology,University of Macao,Avenida da Universidade,Taipa,Macao,China

出　　处：《npj Computational Materials》2016年第1期36-43,共8页计算材料学（英文）

摘　　要：Understanding the nature of all possible ground states and especially magnetic-field-driven phase transitions of antiferromagnets represents a major step towards unravelling the real nature of interesting phenomena such as superconductivity,multiferroicity or magnetoresistance in condensed-matter science.Here a consistent mean-field calculation endowed with antiferromagnetic(AFM)exchange interaction(J),easy axis anisotropy(γ),uniaxial single-ion anisotropy(D)and Zeeman coupling to a magnetic field parallel to the AFM easy axis consistently unifies the AFM state,spin-flop(SFO)and spin-flip transitions.We reveal some mathematically allowed exotic spin states and fluctuations depending on the relative coupling strength of(J,γand D).We build the three-dimensional(J,γand D)and two-dimensional(γand D)phase diagrams clearly displaying the equilibrium phase conditions and discuss the origins of various magnetic states as well as their transitions in different couplings.Besides the traditional first-order type one,we unambiguously confirm an existence of a second-order type SFO transition.This study provides an integrated theoretical model for the magnetic states of collinear antiferromagnets with two interpenetrating sublattices and offers a practical approach as an alternative to the estimation of magnetic exchange parameters(J,γand D),and the results may shed light on nontrivial magnetism-related properties of bulks,thin films and nanostructures of correlated electron systems.

关 键 词：TRANSITIONS magnetic phase 

分 类 号：TG1[金属学及工艺—金属学]