Anomalous thermal expansion and magnetostriction of rare earth compounds under high pressure

Abstract The thermal expansion coefficients of Kondo compounds, CeBe13 and CeRh2Si2, and the magnetostriction of Tb0.3Dy0.7Fe2(Terfenol-D) have been measured at high pressure. By simple analysis using thermodynamical relation, it is found that the density of state at the Fermi level and the Gruneisen parameters Γ of the Kondo compounds decrease rapidly with increasing pressure corresponding to the large pressure-induced enhancement of Kondo temperatures. An anomalous behaviour in the thermal expansion coefficients of CeRh2Si2 is observed at high pressure above T N . This anomaly is suggested as an origin of pressure-induced superconductivity. The giant magnetostriction (GMS) of Terfenol-D is found to be enhanced by applying hydrostatic pressure below 0.5 GPa but GMS decreases above it. These results are discussed briefly by comparing with the previous ones.