D. Yu. Karpenkov, A. Yu. Karpenkov, K. P. Skokov, I. A. Radulov, M. Zheleznyi, T. Faske and O. Gutfleisch

DOI: 10.1103/PhysRevApplied.13.034014

In this work, we develop a comprehensive experimental-theoretical approach for the understanding of multistimuli-responsive caloric materials with first-order transitions and for the optimization of their functional properties.

First, we design and build a PPMS based experimental set-up “MaRS”, that can provide a self-consistent set of parameters, such as simultaneously measured magnetization, M ; volume magnetostriction, ω(H)T; and temperature of the sample, T. Second, using as an example the magnetocaloric LaFe_11.4Si_1.6 compound with a first-order field-induced transition, and based on the Bean-Rodbell model, we develop a model that allows us to describe analytically the behavior of magnetization under different pressures using our M(T) and ω(T) dependencies measured simultaneously at ambient pressure.

Our model also enables estimation of the temperature dependence of compressibility, κ(T), without carrying out complex and time-consuming XRD measurements of lattice parameters under pressure. Additional parameters, such as the thermal expansion coefficient, α(T), and magnetoelastic interaction or effective magnetovolume coupling constant, CMV, can also be determined within the framework of our approach.