Effect of pressure on temperature-induced spin-state transition in La1−xSrxCoO3 single crystals

The temperature dependence of magnetization (M) and resistivity (ρ) of La1−xSrxCoO3(x=0.10, 0.33) single crystals have been analyzed. For x=0.10, the temperature dependence of field-cooled magnetization (MFC) and zero-field-cooled magnetization (MZFC) is similar to that expected for a canonical spin-glass system. The thermal response of MZFC for x=0.33 indicates a glassy ferromagnetic state. We observe that the ferromagnetic transition temperature TC decreases and ρ increases rapidly with increasing pressure (P) for the metallic sample (x=0.33), while the dependence of ρ on P for the insulating sample (x=0.10) is quite complicated; the pressure coefficient of resistivity (dρ/dT) is sensitive to temperature and applied pressure due to the strong interplay between the pressure-induced band broadening and spin-state transition phenomenon. dρ/dT is large and negative at low-pressure and low-temperature regime while small and positive at high pressures (P>5.4 GPa) and high temperatures (T>110 K).