Unconventional metamagnetic phase transition in R2In (R=Nd, Pr) with lambda-like specific heat and nonhysteresis

• Published in: Journal of materials science & technology Vol. 101; pp. 80 - 84
• Main Authors: Cui, Weibin, Yao, Guiquan, Sun, Shengyu, Wang, Qiang, Zhu, Jie, Yang, Sen
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 28.02.2022
• Subjects: Magnetic entropy change; Magnetocaloric effects; Magnetostriction; Metamagnetic transition; Magnetic entropy change; Magnetocaloric effects; Magnetostriction; Metamagnetic transition
• ISSN: 1005-0302; 1941-1162
• DOI: 10.1016/j.jmst.2021.05.055

•The field-triggered metamagnetism with lambda-like peak on the specific heat is found in Nd2In and Pr2In alloys.•Neither thermomagnetic hysteresis nor lattice changes are observable during phase transition.•Giant magnetoentropy changes of 13.2 J kg−1 K−1 and 19.5 J kg−1 K−1 are achieved with enhanced magnetoelastic coupling.•The max adiabatic temperature changes of 6.5 K and 7.4 K are obtained for Nd2In and Pr2In alloys under 7 T.•It is proposed to be from the delocalized 5d electrons evidenced by the negative magnetoresistance. The phase transition of Nd2In and Pr2In has been studied and found to be between the first-order and second-order nature. Hardly any hysteresis nor obvious cell volume changes are presented. Concurrently the field-triggered metamagnetism is demonstrated with lambda-like peak on specific heat curve. For the field change of 7 T, giant magnetic entropy changes of 13.2 J kg−1 K−1 and 19.5 J kg−1 K−1 and adiabatic temperature changes of 6.5 K and 7.4 K have been achieved in Nd2In and Pr2In alloys respectively, which is partially contributed by strong magnetoelastic coupling represented by high saturation magnetostriction of ∼450 ppm. Such unique feature is proposed to be originated from the delocalized 5d electrons, as evidenced by the negative magnetoresistance caused by the phase transition. [Display omitted]