Enhanced negative thermal expansion in La(1-x)Pr(x)Fe10.7Co0.8Si1.5 compounds by doping the magnetic rare-earth element praseodymium.
Experiments have been performed to enhance negative thermal expansion (NTE) in the La(Fe,Co,Si)13-based compounds by optimizing the chemical composition, i.e., proper substitution of La by magnetic element Pr. It is found that increasing the absolute value of the average coefficient of thermal expansion (CTE) in the NTE temperature region (200-300 K) attributes to enhancement of the spontaneous magnetization and its growth rate with increasing Pr content. Typically, the average CTE of La(1-x)Pr(x)Fe10.7Co0.8Si1.5 with x = 0.5 reaches as large as -38.5 × 10(-6) K(-1) between 200 and 300 K (ΔT = 100 K), which is 18.5% larger than that of x = 0. The present results highlight the potential applications of La(Fe,Co,Si)13-based compounds with a larger NTE coefficient.
Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing, P. R. China.
Wen
W
Li
Rongjin
R
Huang
Wei
W
Wang
Jie
J
Tan
Yuqiang
Y
Zhao
Shaopeng
S
Li
Chuanjun
C
Huang
Jun
J
Shen
Laifeng
L
Li