Magnetic and transport properties of Gd1−xCaxCrO3 (x=0.0–0.3): Effect of orbital degeneracy in thermoelectric power

摘要: Abstract Detailed magnetic and transport properties of orthorhombic perovskites ceramics Gd1−xCaxCrO3 (x=0.0–0.3) have been reported. Magnetization measurements under both field cooled cooling (FCC) heating (FCH) protocol reveal magnetization reversal at low temperature field. This indicates clear evidence two sublattices aligned opposite to each other. The effect Gd3+ ion on the decreases largely above x=0.2. nature dependent dc susceptibility (χ) was Curie–Weiss like transition (Tmax) with an effective moment (μeff) that decreased increase Ca concentration. These orthochromites exhibit a independent, large positive thermoelectric power or Seebeck coefficient (S) value 200 K. Upon Ca2+ substitution, concomitant decrease S is found. evolution as function hole concentration (Cr4+) can be well fitted by modified Heikes formula taking into account orbital degeneracy related Cr3+ Cr4+.