Magnetic properties of La1-xPrxCrO3

Magnetic properties have been investigated for the perovskite La1-xPrxCrO3 (0 less than or equal to x less than or equal to 1), which is a solid solut ion series between LaCrO3 (x = 0) and PrCrO3 (x = 1), based on de magnetiza tion and neutron diffraction measurements. The crystal structures were assi gned to an orthorhombic perovskite type (space group Pnma) in the whole com position region. Canted-antiferromagnetic order is commonly observed at the Neel temperatures (T-N) of 288-240 K. In low applied magnetic fields (less than or similar to 5000 Oe), the solid solutions with a wide composition r ange of 0.2 less than or equal to x less than or equal to 0.8 exhibit disti nct negative magnetization below the compensation temperatures (T-comp) (le ss than or similar to 230 K). It is characteristic that the absolute values of such magnetization are much larger (by similar to 250 times in the larg est case with the applied field of 100 Oe) than the positive ordered magnet ization observed between T-N and T-comp. Neutron diffraction data for La0.5 Pr0.5CrO3 showed the existence of G(y)-type (G(z) for Pbnm) antiferromagnet ic order of Cr3+ moments with no crystallographic change below TN. Consider ing the fact that the present behavior is similar to that in GdCrO3, this i s plausibly ascribed to the antiparallel coupling of the Pr3+ moments and t he canted Cr3+ moments. (C) 2001 Academic Press.