Three-dimensional critical behavior and magnetocaloric effect in Yb14MnSb11

Systematic investigations were performed on the nature of the magnetic properties of Yb14MnSb11, which is the first ferromagnetic Kondo lattice compound in the underscreened limit and one of the highest thermoelectrically efficient materials with p-type conduction. The Rhode-Wohlfarth ratio (RWR) is estimated to be 1.01, which demonstrates the localized nature of the ferromagnetism in Yb14MnSb11, consistent with the predicted Ruderman-Kittel-Kasuya-Yosida (RKKY) like exchange interaction. Detailed analyses on critical behavior indicate a second-order ferromagnetic phase transition with critical exponents /3 = 0.307(2), y = 0.923(9), and 8 = 4.003(4), demonstrating a three-dimensional critical behavior with long-range interaction. Furthermore, the magnetocaloric effect and relative cooling power are estimated to be 0.772 J kg-1 K-1 and 16.43 J kg-1 at 5 T, respectively. The magnetic transition temperature of TC = 51.9(3) K is strictly estimated by evaluating the magnetic change of specific heat [⠁Cp(T, H)]. The rare d-electron ferromagnetic Kondo lattice, small magnetocaloric effect, and high-temperature large thermoelectric efficiency making Yb14MnSb11 to be a system of considerable interest.