Search

New phases Sr8ARe3Cu4O24 (A=Sr,Ca) were discovered under high-pressure/high-temperature condition. X-ray powder diffraction and electron diffraction studies for these phases indicated that they have an ordered perovskite-type structure with cubic lattices of ∼8 A˚. They showed ferromagnetism at room temperature when they were synthesized under high-oxygen-pressure condition. The Ca-containing phase has a very high Tc of 440 K with a spontaneous magnetization of ∼1 μB/f.u. [Copyright &y& Elsevier]

Abstract: Magnetic properties of the calcium ferrite-type are reported. The static susceptibility data reveal a cusp at , suggesting a magnetic glassy transition. Although the crystal structure is essentially different from that of the spinel , the compound shows a similarity of the frustrated magnetism of the spinel. The probable magnetic frustration of the calcium ferrite-type compound might be due to a freezing of geometrically frustrated Mn magnetic moments in a triangular-like alignment. [Copyright &y& Elsevier]