Ba＿（1－x）Sr＿xTiO＿3（0≤X≤1）固溶体的合成及性质研究

Studies on Sythesis and Properties of Ba_(1-x)Sr_(x)TiO_3(0≤x≤1)

本文用四氯化钛、氯化钡、氯化锶分别作为钛、钡、锶源，用草酸作沉淀剂，首先在６５℃反应制得Ｂａ＿（１－Ｘ）Ｓｒ＿ＸＴｉＯ（Ｃ＿２Ｏ＿４）＿２·４Ｈ＿２Ｏ先驱物，在５Ｏ℃烘干后，再于８００℃的烧１小时，得到Ｂａ＿（１－Ｘ）Ｓｒ＿ＸＴｉＯ＿３白色粉末。经Ｘ─射线衍射分析证明，当ｘ分别为０和１时，产品分别为四方晶系钛酸钡和立方晶系钛酸锶，其它为由四方晶系向立方晶系过渡的固溶体。晶胞参数计算可知，该固溶体为完全互溶固溶体，结果符合Ｖｅｇａｒｄ定律。电镜形貌分析证明粒度为０．３～０．５μｍ。制陶试验证实，ＢａＴｉＯ＿３纯相掺锶后，居里点普遍前移，介电常数均有所提高，当产品组成为Ｂａ＿（０．９）Ｓｒ＿（０．１）ＴｉＯ＿３时，居里点前移２０℃，介电常数为７４００，比钛酸钡纯相的介电常数提高了４倍。

The synthesis and properties of the solid solution, Ba_(1-x)Sr_(x)TiO_3(0≤x≤1).were studied.The synthesis was achieved by use of precursor method. Firstly,pure BaTiO_3was prepared,then,a stoichiometrical mixture of BaTiO_3,TiCl_4 and BaCl_2 was allowed toreact with oxalic acid under 65℃ with the result that BaTiO(C_2O_4)_2· 4H_2O was obtained.After sintering at 800℃,the pure phase of tetragonal system BaTiO_3 was obtained.Follow-ing the same procedure, the pure phase of cubic system SrTiO_3 was obtained by substi-tuting Sr￣(2+) for Ba￣(2+). According to the preceding method Ba_(1-x)Sr_(x)TiO_3 solid solutions wereobtained by partly substituting Sr￣(2+)for Ba￣(2+) in BaTiO_3 with mole ratio of Ba￣2+) to Sr￣(2+)to be 0.98 :0.02.0.96 :0.04.……0.10 :0.90. X-ray diffraction analysis andd-pacing-component figures of the series of the solid solutions proved that the com-pounds are mutual miscible in the solid solutions,and the results comform to Vegard Law.The making ceramics results showed that adulterating with strontium(X<2)in BaTiO_3pure phase obviously improved the ε,but no regularity was observed.When the amount ofstrontium adulterated amounts to 10%,we get Ba_0.9Sr0.1TiO_3 whose dielectric constant is 4times higher than that of BaTiO_3 pure phase.