SPIN-GLASS BEHAVIOR AND MAGNETIC PHASE-DIAGRAM OF LA1-XSRXCOO3 LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.5) STUDIED BY MAGNETIZATION MEASUREMENTS

Magnetic properties of La1-xSrxCoO3 (0 less-than-or-equal-to x less-th an-or-equal-to 0.5) have been studied by magnetization measurements in low magnetic fields. It has been found that there exist spin-glass (0 < x less-than-or-similar-to 0.18) and cluster-glass (0.18 less-than-o r-similar-to x less-than-or-equal-to 0.5) regions. Ferromagnetic long- range order previously reported does not take place. Spin-glass behavi or is ascribed to the frustration of random competing exchange interac tions, namely the ferromagnetic double-exchange interaction between Co 3+ and Co4+ and the antiferromagnetic one between like spins.