Alternating current magnetic susceptibility measurements in La1−xSrxCoO3 (x⩽0.30) below 300 K

MIRA, J.; RIVAS, J.; SÁNCHEZ, R. D.; SEÑARÍS-RODRÍGUEZ, M. A.; FIORANI, D.; RINALDI, D.; CACIUFFO, R.

JOURNAL OF APPLIED PHYSICS

AMER INST PHYSICS

Lugar: New York; Año: 1997 vol. 81 p. 5753 - 5755

0021-8979

A dynamical magnetic susceptibility study on La1−xSrxCoO3 samples obtained by a coprecipitation method is reported for x⩽0.30. For x<0.20 differences between zero field cooled and field cooled dc magnetic susceptibility appear at a temperature Ta below the Curie point, TC≈240 K, as well as a magnetic freezing point at a temperature Tb<Ta. Alternating current magnetic susceptibility shows two maxima at these temperatures, which is interpreted as the evidence of different interaction processes between ferromagnetic clusters mediated by a matrix of changing spin-state Co3+ ions. For x⩾0.20 an unique blocking process seems to take place due to the percolation of the ferromagnetic clusters, making unimportant the contribution of the matrix.