過渡金屬磷酸鹽之合成,晶體結構及磁性研究

Abstract

第壹章:新穎鹼土族過渡金屬磷酸鹽 AM3(P2O7)2 (A=鈣 鍶 鋇,M=鐵 鈷 鎳)晶體AM3(P2O7)2以高壓水熱法在500度下合成,以X光單晶和粉末繞射完 成結構鑑定.其結構是共邊的MO6八面體形成的Z字形無限長鏈,鏈與鏈間以 P2O7雙聚體相互連接形成此三度空間的架構,而鹼土族金屬充填在沿b軸的 隧道中.SrFe3(P2O7)2在26K-300K呈順磁性質,其有效磁矩為5.07B.M., 在26K以下磁化率增加快速,在6K達最大值然後迅速減少.Mossbauer光譜也 證實Fe(II)的存在.第貳章:新潁鈉鈷磷酸鹽晶體NaCo3(HPO4)2(PO4)以高 壓水熱法在230度下合成,以X光單晶繞射完成結構鑑定.其結構以CoO6八面 體共用不對稱邊形成無限長鏈,鏈與鏈間以PO4,HPO4四面體連接形成三度 空間網狀孔洞架構,Na離子充填在沿c軸的隧道中.我們將討論此無機化合 物的合成,結構,磁性及熱分析等. AM3(P2O7)2 Diphosphate of the stoichiometry AM3(P2O7)2 (A= alkaline-earth metals, M= Fe, Co, Ni) have been synthesized and structurally characterized by single-crystal and powder X-ray diffraction. The structure consists of zigzag infinite chains of MO6 groups to form a three-dimensional architecture with channels parallel to the b axis. Alkaline earth metals are located. NaCo3(HPO4)2(PO4) Crystals of NaCo3(HPO4)2(PO4) have been grown hydrothermally at 230 degreeC and the crystal stucture characterized by single- crystal X-ray diffraction. The structure consists of infinite chains of CoO6 octahedra sharing skew edges.