Itinerant magnetism in the half-metallic Heusler compound Co2HfSn: Evidence from critical behavior combined with first-principles calculations

doi:10.1103/PhysRevB.103.094425

	Itinerant magnetism in the half-metallic Heusler compound Co2HfSn: Evidence from critical behavior combined with first-principles calculations
	Rahman, Azizur 7; Rehman, Majeed Ur 8; Zhao, Hongze 7; Liu, Wei 5; Wang, Jianlin 1,6; Lu, Yalin 1,6; Ruan, Keqing 2,7; Dai, Rucheng 3; Wang, Zhongping 3; Tao, Xiaoping 3
刊名	PHYSICAL REVIEW B
	2021-03-17
卷号	103
ISSN号	2469-9950
DOI	10.1103/PhysRevB.103.094425
通讯作者	Zhang, Zengming(zzm@ustc.edu.cn)
英文摘要	Co-2-based Heusler alloys show diverse magnetic behavior, extending from the localized Heisenberg to the delocalized itinerant, and thus cannot be generalized with one specific model. Therefore, we bring together experiments and first-principles calculations to reveal the origin of long-range ferromagnetism in the Co-2-based Heusler alloy Co2HfSn. The precise value of the critical exponents beta = 0.471( 4), gamma = 1.02( 4), and delta = 3.273(5) with the Curie temperature (T-c = 430 K) were determined experimentally by means of different analytical methods such as modified Arrott plot analysis, the Kouvel-Fisher method, and critical isotherm analysis. The deduced critical exponents belong to the theoretical prediction of the three-dimensional meanfield model. The magnetic exchange distance is found to decay as J(r) similar to r(-4.52), indicating the long-range magnetic interaction in Co2HfSn. Moreover, the magnetic entropy change - Delta S-M features a maximum at T-c, i.e., - Delta S-M(max) similar to 29.87(6) J kg(-1) K-1 at 5 T, whereas power law fitting of - Delta S-M(max) M with H gives n' = 0.663(5), also confirming the mean-field-type magnetic interaction in Co2HfSn. Meanwhile, in order to explore the origin of long-range ferromagnetic ordering in Co2HfSn, spin-polarized density functional theory calculations were employed in this study. No stable antiferromagnetic solution with stable local magnetic moments at the Co or Hf site was observed in our fixed spin moment simulation, revealing that Co2HfSn is a highly itinerant magnet with a long-range ferromagnetic solution together with robust half-metallic conduction stable against thermal excitation higher than room temperature. Furthermore, our theoretical analysis shows that Co2HfSn belongs to an unconventional family of itinerant magnetism. Both the 100% spin-polarized metallicity and ferromagnetism arise from the Co d orbitals, causing it to be unique compared to the conventional itinerant family of Ni, Co, or Fe, where magnetism and metallicity originate from different orbitals characters.
资助项目	National Natural Science Foundation of China[12074360] ; National Natural Science Foundation of China[21905263] ; National Natural Science Foundation of China[12004366] ; Science Challenge Project[TZ2016001]
WOS关键词	CRITICAL EXPONENTS ; FERROMAGNETISM ; TRANSITION ; CO2FEAL ; ALLOYS
WOS研究方向	Materials Science ; Physics
语种	英语
出版者	AMER PHYSICAL SOC
WOS记录号	WOS:000646413200006
资助机构	National Natural Science Foundation of China ; Science Challenge Project
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/122391]
专题	中国科学院合肥物质科学研究院
通讯作者	Zhang, Zengming
作者单位	1.Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei 230026, Peoples R China 2.Univ Sci & Technol China, Chinese Acad Sci, Sch Phys Sci, Key Lab Strongly Coupled Quantum Matter Phys, Hefei 230026, Anhui, Peoples R China 3.Univ Sci & Technol China, Ctr Phys Expt, Hefei 230026, Peoples R China 4.Chinese Acad Sci, High Magnet Field Lab, Hefei 230031, Peoples R China 5.Anhui Univ, Inst Phys Sci & Informat Technol, Hefei 230601, Peoples R China 6.Univ Sci & Technol China, Anhui Lab Adv Photon Sci & Technol, Hefei 230026, Peoples R China 7.Univ Sci & Technol China, Dept Phys, Hefei 230026, Peoples R China 8.Shenzhen Univ, Coll Phys & Optoelect Engn, Nanhai Ave 3688, Shenzhen 518060, Guangdong, Peoples R China
推荐引用方式 GB/T 7714	Rahman, Azizur,Rehman, Majeed Ur,Zhao, Hongze,et al. Itinerant magnetism in the half-metallic Heusler compound Co2HfSn: Evidence from critical behavior combined with first-principles calculations[J]. PHYSICAL REVIEW B,2021,103.
APA	Rahman, Azizur.,Rehman, Majeed Ur.,Zhao, Hongze.,Liu, Wei.,Wang, Jianlin.,...&Zhang, Zengming.(2021).Itinerant magnetism in the half-metallic Heusler compound Co2HfSn: Evidence from critical behavior combined with first-principles calculations.PHYSICAL REVIEW B,103.
MLA	Rahman, Azizur,et al."Itinerant magnetism in the half-metallic Heusler compound Co2HfSn: Evidence from critical behavior combined with first-principles calculations".PHYSICAL REVIEW B 103(2021).