一、引言 热液结晶作用对处于较高氧化态的过渡金属化合物的生长是特别有意义的,因为在较低的生长温度下,要稳定这些氧化态不需要高的氧压力。稀土铁石榴石和正铁氧体(Orthoferries)单晶近来特别重要,因为它们的磁学性质使它们在泡畴存贮器中很有用。研究Y_2O_3-Fe_2O_3-H_2O相图表明在此系统中适中温度的情况下,有时磁铁矿(Fe_3O_4)能够形成。尽管综合诺尔汤(Norton)和瓦格曼(Wagman)的资料表明 I. INTRODUCTION The hydrothermal crystallization is of particular interest for the growth of transition metal compounds in higher oxidation states, since high oxygen pressures are not required to stabilize these oxidation states at lower growth temperatures. Rare earth iron garnet and Orthoferries single crystals have recently become particularly important because their magnetic properties make them useful in bubble domain memories. The study of Y_2O_3-Fe_2O_3-H_2O phase diagram shows that magnetite (Fe_3O_4) can be formed under the moderate temperature in this system. Despite the data from Norton and Wagman