title: Unusual ferromagnetic critical behavior owing to short-range antiferromagnetic correlations in antiperovskite Cu(1-x)NMn(3+x) (0.1 ≤ x ≤ 0.4).
abstract: For ferromagnets, varying from simple metals to strongly correlated oxides,the critical behaviors near the Curie temperature (T(C)) can be grouped into several universal classes. In this paper, we report an unusual critical behavior in manganese nitrides Cu(1-x)NMn(3+x) (0.1 ≤ x ≤ 0.4). Although the critical behavior below T(C) can be well described by mean field (MF) theory, robust critical fluctuations beyond the expectations of any universal classes are observed above T(C) in x = 0.1. The critical fluctuations become weaker when x increases, and the MF-like critical behavior is finally restored at x = 0.4. In addition, the paramagnetic susceptibility of all the samples deviates from the Curie-Weiss (CW) law just above T(C). This deviation is gradually smeared as x increases. The short-range antiferromagnetic ordering above T(C) revealed by our electron spin resonance measurement explains both the unusual critical behavior and the breakdown of the CW law.
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Jianchao
authors.initials: J
authors.lastname: Lin
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Tong
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Dapeng
authors.initials: D
authors.lastname: Cui
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Yang
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Lin
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Bosen
authors.initials: B
authors.lastname: Wang
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Tong
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Youming
authors.initials: Y
authors.lastname: Zou
authors.affiliation: 1] Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China [2] High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China [3] Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Sun