Effect of pressure on the magnetic, transport, and thermal-transport properties of the electron-doped manganite CaMn_(1-x)Sb_xO_3

摘要

We have demonstrated the effect of hydrostatic pressure on magnetic and transport properties, and thermal-transport properties in the electron-doped manganite CaMn_(1-x)Sb_xO_3. The substitution of Sb~(5+) ion for Mn ~(4+) site of the parent matrix causes one-electron doping with the chemical formula CaMn_(1-x)Sb_xO_3 accompanied by a monotonous increase in unit-cell volume as a function of x. Upon increasing the doping level of Sb, the magnitudes of both electrical resistivity and negative Seebeck coefficient are suppressed at high temperatures, indicating the electron doping. Anomalous diamagnetic behaviors at x = 0.05 and 0.08 are clearly observed in the field cooled dc magnetization. The effect of hydrostatic pressure on dc magnetization is in contrast to the chemical pressure effect due to Sb doping. The dynamical effect of ac magnetic susceptibility measurement points to the formation of the magnetically frustrated clusters such as FM clusters embedded in canted AFM matrix.