R. Font, E. Marín, A. Lara-Bernal, O. Ra, mond., A. Calderón, J. Portelles, and J. Siqueiros, Room temperature thermal properties of Pb(Fe$_{1 /2}$Nb$_{1 / 2}$)O$_{3}$ ferroelectromagnetic ceramics, Rev. Mex. Fís. 57, (2011).