Frustrated Orders in the Perovskite (Bi_(0.5)Sr_(0.5))CrO3

摘要

A new perovskite, (Bi_(0.5)Sr_(0.5))CrO3, has been prepared at 1000 °C and ambient pressure, although BiCrO3 and SrCrO3 are both high pressure phases. The crystal structure is rhombohedral (R3c, a = 5.4652(5) and c = 13.3502(2) A at 300 K). Well-defined local Bi~(3+) displacements are evident despite an absence of long-range Bi/Sr cation order, but the degree of ferroelectric order is unclear. Long range G-type antiferromagnetic order occurs below 30 K; however, the low value of the ordered magnetic moment (1.2 μ_B), a high frustration index, and low temperature divergence of zero field and field cooled susceptibilities show that a substantial glassy component is also present.