摘要
报道了在TiO2-La2O3-M2O-H2O水热体系中,新型钛镧酸盐M0.5La0.5TiO3(M=La,Ag0.66Na0.33,Li0.6Na0.4)的水热合成,用XRD、SEM、TEM、ICP、DTA-TG、IR和ac阻抗分析技术进行了结构表征.讨论了水热合成反应体系pH、反应混合物的组成比以及晶化温度等因素对合成的影响.XRD分析表明,Na0.5La0.5TiO3和Ag0.33Na0.17La0.5TiO3具有立方结构,晶胞参数分别为a=0.3877nm和a=0.3890nm.Li0.3Na0.2La0.5TiO3具有正交结构,a=0.3894nm,b=0.3912nm,c=0.3890nm.TEM测定显示Na0.5La0.5TiO3和Ag0.33Na0.17La0.5TiO3是纳米尺度晶体,平均粒度分别为50nm和70nm.Li0.3Na0.2La0.5TiO3的平均粒度分布为5μm.Ag0.33Na0.17La0.5TiO3在440℃的电导率为1.9×10-5S/cm,Li0.3Na0.2La0.5TiO3的电导率为1.5×10-6S/cm.
Novel perovskite titanlanthanates, M 0.5 La 0.5 TiO 3 (M=Na, Ag 0.66 Na 0.33 , Li 0.6 Na 0.4 ) were hydrothermally synthesized under mild conditions, and characterized by means of X ray diffraction(XRD), scanning electron microscopy(SEM), differential thermal and thermogravometric analyses(DTA TG), inductively coupled plasma analysis(ICP) and infrared spectroscopy(IR). The ionic transport properties were measured by an ac impedance method. Some factors, e.g., crystallization temperature, pH, and Ti/La molar ratio in reaction mixture dominate the hydrothermal syntheses of the single phase products. Na 0.5 La 0.5 TiO 3 and Ag 0.33 Na 0.17 La 0.5 TiO 3 crystallized in cubic system with cell parameters: a =0.387 7 nm and a =0.389 0 nm, respectively, whereas Li 0.3 Na 0.2 La 0.5 TiO 3 has orthorhombic symmetry with parameters a =0.389 4 nm, b =0.391 2 nm and c =0.3890 nm. Under a similar experimental condition, the average particle sizes of the products are 50 nm for Na 0.5 La 0.5 TiO 3 , 70 nm for Ag 0.33 Na 0.17 La 0.5 TiO 3 and 5 μm for Li 0.3 Na 0.2 La 0.5 TiO 3. An ac impedance study indicates that conductivities of Ag 0.33 Na 0.17 La 0.5 TiO 3 and Li 0.3 Na 0.2 La 0.5 TiO 3 at 713 K are 1×10 -5 and 1×10 -6 S/cm, respectively.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1998年第3期340-344,共5页
Chemical Journal of Chinese Universities
基金
国家自然科学基金
关键词
水热合成
纳米晶体
导电性质
钛镧酸盐
Hydrothermal syntheses, Nanocrystalline, Conductivity, Titanlanthanate