Finite Temperature Magnetism in the Triangular Lattice Antiferromagnet KErTe_(2)  

作　　者：Weiwei Liu Zheng Zhang Dayu Yan Jianshu Li Zhitao Zhang Jianting Ji Feng Jin Youguo Shi Qingming Zhang 刘维维;张政;闫大禹;李建树;张志涛;籍建葶;金峰;石友国;张清明(Department of Physics,Renmin University of China,Beijing 100872,China;Beijing National Laboratory for Condensed Matter Physics,and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions,High Magnetic Field Laboratory,Chinese Academy of Sciences,Hefei 230031,China;School of Physical Science and Technology,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]Department of Physics,Renmin University of China,Beijing 100872,China [2]Beijing National Laboratory for Condensed Matter Physics,and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [3]Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions,High Magnetic Field Laboratory,Chinese Academy of Sciences,Hefei 230031,China [4]School of Physical Science and Technology,Lanzhou University,Lanzhou 730000,China

出　　处：《Chinese Physics Letters》2024年第9期140-150,共11页中国物理快报（英文版）

基　　金：supported by the National Science Foundation of China(Grant Nos.U1932215 and 12274186);the National Key Research and Development Program of China(Grant No.2022YFA1402704);the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB33010100);the Synergetic Extreme Condition User Facility(SECUF)。

摘　　要：After the discovery of the ARECh_(2)(A=alkali or monovalent ions,RE=rare-earth,Ch=chalcogen)triangular lattice quantum spin liquid(QSL)family,a series of its oxide,sulfide,and selenide counterparts has been consistently reported and extensively investigated.While KErTe_(2) represents the initial synthesized telluride member,preserving its triangular spin lattice,it was anticipated that the substantial tellurium ions could impart more pronounced magnetic attributes and electronic structures to this material class.This study delves into the magnetism of KErTe_(2) at finite temperatures through magnetization and electron spin resonance(ESR)measurements.Based on the angular momentum J after spin-orbit coupling(SOC)and symmetry analysis,we obtain the magnetic effective Hamiltonian to describe the magnetism of Er^(3+)in R3m space group.Applying the mean-field approximation to the Hamiltonian,we can simulate the magnetization and magnetic heat capacity of KErTe_(2) in paramagnetic state and determine the crystalline electric field(CEF)parameters and partial exchange interactions.The relatively narrow energy gaps between the CEF ground state and excited states exert a significant influence on the magnetism.For example,small CEF excitations can result in a significant broadening of the ESR linewidth at 2 K.For the fitted exchange interactions,although the values are small,given a large angular momentum J=15/2 after SOC,they still have a noticeable effect at finite temperatures.Notably,the heat capacity data under different magnetic fields along the𝑐axis direction also roughly match our calculated results,further validating the reliability of our analytical approach.These derived parameters serve as crucial tools for future investigations into the ground state magnetism of KErTe_(2).The findings presented herein lay a foundation for exploration of the intricate magnetism within the triangular-lattice delafossite family.

关 键 词：TRIANGULAR HAMILTONIAN MAGNETIZATION 

分 类 号：O469[理学—凝聚态物理]