The chromium(II) orthophosphate α-Cr 3 (PO 4 ) 2 is a weak ferrimagnet with the Curie temperature T C = 29 K confirmed by a λ-type peak in specific heat. Dominant antiferromagnetic interactions in this system are characterized by the Weiss temperature Θ = 96 K, indicating an intermediate frustration ratio Θ/T C ∼ 3. In its magnetically ordered states α-Cr 3 (PO 4 ) 2 exhibits a remarkable sequence of temperature-induced magnetization reversals sensitive to the protocol of measurements, i.e., either field-cooled or zero-field-cooled regimes. The reduction of the effective magnetic moment 4.5 μ B / Cr2 + , as compared to the spin-only moment 4.9 μ B / Cr2 + , cannot be ascribed to the occurrence of the low-spin state in any crystallographic site of the Jahn-Teller active 3d4 Cr2 + ions. X-ray absorption spectra at the K edge indicate divalent chromium and unravel the high-spin state of these ions at the L 2,3 edges. Weak ferrimagnetism and multiple magnetization reversal phenomena seen in this compound could be ascribed to incomplete cancellation and distortion of partial spontaneous magnetization functions of Cr2 + in its six crystallographically inequivalent positions.
|頁（從 - 到）||1-7|
|期刊||Physical Review B - Condensed Matter and Materials Physics|
|出版狀態||Published - 18 1月 2012|