1. Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Anhui Hefei 2. University of Science and Technology of China, Anhui Hefei 3. High Magnetic Field Laboratory, Chinese Academy of Sciences, Anhui Hefei
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DOI:
10.7502/j.issn.1674-3962.2015.07.06
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Abstract:
Antiperovskite manganese nitrides have attracted much attention recently because of the negative thermal expansion (NTE) they display. A new series of anti-perovskite manganese nitrides Ga1-xN0.8Mn3+x(0<x≤3) were prepared using solid–state reaction method. In the present work, the negative thermal expansion (NTE) and the electrical transport were studied. With the increment of Mn-doping level, the temperature span of the magnetovolume effect not only broadens but also shifts toward lower temperatures. The temperature span of NTE is 292-339K and 256-309K, and the corresponding coefficient of linear thermal expansion is -48ppm/K and -42ppm/K, respectively. An abnormal behavior of resistivity was observed, in line with the contraction of the lattice. The NTE behaviors may be attributed to the disturbance of the Γ5g antiferromagnetic ground state by partially substituting the Ga atoms with Mn.