New insight into magneto-structural phase transitions in layered TbMn2 Ge2-based compounds

Authors

Chunsheng Fang, University of WollongongFollow
Guoxing Li, University of Wollongong, Jilin University
Jian Li Wang, University of WollongongFollow
Wayne D. Hutchison, University of New South Wales
Qing Yon Ren, University of New South Wales
Zhenyan Deng, Shanghai University
Guohong Ma, Shanghai UniversityFollow
Shi Xue Dou, University of WollongongFollow
Stewart J. Campbell, University of New South WalesFollow
Zhenxiang Cheng, University of WollongongFollow

RIS ID

113469

Publication Details

Fang, C., Li, G., Wang, J., Hutchison, W. D., Ren, Q. Y., Deng, Z., Ma, G., Dou, S., Campbell, S. J. & Cheng, Z. (2017). New insight into magneto-structural phase transitions in layered TbMn₂ Ge₂-based compounds. Scientific Reports, 7 45814-1-45814-14.

Abstract

The Tb1−xYxMn2Ge2 series (x = 0, 0.1, 0.2) compounds are found to exhibit two magnetic phase transitions with decreasing temperature: from the paramagnetic state to the antiferromagnetic interlayer state at TNinter and from an antiferromagnetic interlayer structure to a collinear ferrimagnetic interlayer structure at TCinter. Compared with the slight change of TNinter (409 K, 410 K and 417 K for x = 0, 0.1 and 0.2 respectively), the replacement of Y for Tb leads to a significant decrease in TCinter from 97.5 K for x = 0 to 74.6 K for x = 0.2. The variation in TCinter can be ascribed to the combination of two effects: (1) chemical pressure and (2) magnetic dilution effect by Y substitution for Tb. Besides, a strong anisotropic magnet-volume effect has been detected around TCinter in all compounds with Δa/a = 0.125%, 0.124% and 0.130% for x = 0, 0.1 and 0.2, respectively while no obvious effect is detected along the c-axis. The maximum magnetic entropy change were found to be −ΔSmax = 9.1 J kg−1 K−1, 11.9 J kg−1 K−1 and 6.3 J kg−1 K−1 with a field change from 0 T to 5 T for x = 0, 0.1, 0.2 respectively.