Large Linear Negative Thermal Expansion in NiAs-type Magnetic Intermetallic Cr–Te–Se Compounds
Jiawang Xu, Xinqi Zheng, Shuxian Yang, Lei Xi, Shouguo Wang, Lei Zhang, Wenyun Yang, Jinbo Yang, Xiaobai Ma, Dongfeng Chen, Lunhua He, Sihao Deng, Jingyan Zhang, Yanfei Wu, Baogen Shen
Abstract
A large linear negative thermal expansion (NTE) and expanded NTE temperature range (ΔTNTE) were obtained in magnetoelastic CrTe1–xSex (0 ≤ x ≤ 0.15) compounds. For CrTe compound, its thermal expansion coefficient of volume (αV) was calculated to be −28.8 ppm K–1 with the temperature ranging from 280 to 340 K. Substituting Te with Se atoms, the NTE behavior and magnetic properties can be well manipulated. With increasing Se in CrTe1–xSex (0 ≤ x ≤ 0.15) compounds, the ΔTNTE increases from 60 K (280–340 K for x = 0), to 80 K (240–320 K for x = 0.05), to 95 K (200–295 K for x = 0.1), and finally to 100 K (170–270 K for x = 0.15). Furthermore, a linear NTE remains independent of temperature for samples with x ≤ 0.1. The relationship between tunable NTE and magnetic properties was analyzed in detail, indicating that the NTE in CrTe1–xSex compounds originates from the magnetovolume effect (MVE).