MAGNETIC-PROPERTIES OF TETRAVALENT PRASEODYMIUM PEROVSKITES BAPRO3, BACEYPR1-YO3, AND SRYBA1-YPRO3

Tetravalent praseodymium perovskites BaPrO3, BaCey Pn(1-y)O(3), and SryBa1-yPrO3 were prepared, and their magnetic susceptibilities were measured in the temperature range between 4.2 and 300 K. Magnetic ordering found in the BaPrO3 (the transition temperature is 11.6 K) is weakened with substitution of Sr for Pa and much more weakened with substitution of Ce for Pr. Above this transition temperature, the susceptibility decreases anomalously with increasing temperature. A magnetic hysteresis was found at 4.5 K for all the compounds studied here, The magnetic susceptibility above the transition temperature is composed of a Curie-Weiss term associated with a small effective magnetic moment of Pr4+ and a large temperature-independent paramagnetism, The effective magnetic moment of the Pr4+ ion in SryBa1-yPrO3 increases with strontium concentration (y). This result is in accordance with the result obtained from the electron paramagnetic resonance spectrum of Pr4+ doped in SryBa1-yCeO3. (C) 1995 Academic Press, Inc.