KKR-CPA-LDA计算方法对CuMnAl和CoMnAl以及CuCoMnAl合金的磁性研究  

Magnetism research on CuMnAl,CoMnAl and CuCoMnAl alloys by KKR-CPA-LDA calculation

作　　者：冯琳[1] 朱志永[1] 朱伟[1] 刘恩克[1] 唐晓丹[1] 钱金凤[1] 吴光恒[1] 孟凡斌[2] 刘何燕[2] 罗鸿志[2] 李养贤[2] 

机构地区：[1]中国科学院物理研究所磁学国家重点实验室,北京100190 [2]河北工业大学材料科学与工程学院,天津300130

出　　处：《物理学报》2010年第9期6575-6579,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10774178;50771103);北京市教育委员会学科与研究生教育建设项目专项资助的课题~~

摘　　要：采用KKR-CPA-LDA方法研究了CuMnAl,CoMnAl和CuCoMnAl四元合金中磁性原子磁矩和Co-Mn间的交换作用.通过与实验结果对比,揭示了Mn的磁矩和Co的磁矩以及它们的相互作用随成分变化的规律.研究发现,在Cu50Mn25+xAl25-x合金中超过化学配比并占据Al位的Mn原子是反铁磁的,而且由于近邻环境的不同,其磁矩大于原有Mn原子的磁矩.在Co50Mn25+xAl25-x合金中,随着Mn含量的增大,Mn原子的磁矩保持不变,而Co原子的磁矩单调增大.在Cu50-xCoxMn25Al25四元合金中,随着Co对Cu的替换,Mn原子磁矩的减小引起了Co原子磁矩的减小.这些结果揭示了Co磁矩会受到Mn磁矩影响,两者磁矩值是正相关的.同时,研究结果指出,Co-Mn之间的交换作用也因添加Mn而增强.Co-Mn间的交换作用并非仅仅与Co的存在有关,其中也包含了Mn原子的贡献.Comparing with the experimental data, the composition dependence of atomic moment and Co-Mn exchange interaction in CuMnAl,CoMnAl and CuCoMnAl alloys have been investigated by KKR-CPA-LDA calculation. It has been found that,due to the different surrounding environments,the magnetic moment of excess Mn atom occupying Al sites is larger than that of the original Mn atoms on B sites in Cu50 Mn25 ＋ x Al25-x alloys. When the Mn content increases in Co50 Mn25 ＋ xAl25-x alloys,the moment of Co atom increases monotonically,while the Mn moment almost has the same value. In Cu50-x CoxMn25Al25 alloys,it has been revealed that the moment of Co decreases resulting from the decrease of the moment of Mn atom with the substitution of Co for Cu. These results indicate that the atomic moments of Mn and Co atoms are positively related. It has also been found that the Co-Mn exchange interaction can be enhanced by increasing Mn content and its strength comes not only from the added Co but also from the contribution of Mn.

关 键 词：KKR-CPA-LDA计算 Co-Mn间交换作用 

分 类 号：O482.5[理学—固体物理]