Synthesis of (NH4)2XLa1−XSrX[Fe(CN)6]·nH2O from two heteronuclear complexes La[FeIII(CN)6]·5H2O and (NH4)2Sr[FeII(CN)6] by mechanochemical process

• Published in: Journal of the Ceramic Society of Japan 2013/01/01, Vol.121(1409), pp.21-25
• Main Authors: AONO, Hiromichi, KAN, Tomoya, ITAGAKI, Yoshiteru, YAMAGUCHI, Ken-ichi, ITOH, Shun, KURIHARA, Masato, SAKAMOTO, Masatomi
• Format: Article
• Language: English
• Subjects: (NH4)2Sr[Fe(CN)6]; Heteronuclear complex; La1−XSrXFeO3; La[Fe(CN)6]·5H2O; Mechanochemical reaction; X-ray diffraction
• ISSN: 1882-0743; 1348-6535
• DOI: 10.2109/jcersj2.121.21

A heteronuclear (NH4)2Sr[FeII(CN)6] complex having a tetragonal phase was synthesized from Sr(NO3)2 and (NH4)4[FeII(CN)6]·nH2O. A single phase of the heteronuclear (NH4)2XLa1−XSrX[Fe(CN)6]·nH2O complex was synthesized by the coprecipitation for two heteronuclear hexacyano complexes of La[FeIII(CN)6]·5H2O and (NH4)2Sr[FeII(CN)6]. In this chemical method, the X value (Sr content) for the complex was lower than that of the starting material. This (NH4)2XLa1−XSrX[Fe(CN)6]·nH2O complex was also obtained by a mechanochemical reaction using a planetary ball-mill for two complexes (Total 0.01 mol = ca. 4 g) of (1 − X)La[FeIII(CN)6]·5H2O and X(NH4)2Sr[FeII(CN)6] with a small amount (5 ml) of methanol. The hydration number calculated from the elemental analysis agreed with the estimated values when a hexagonal single (NH4)0.8La0.6Sr0.4[Fe(CN)6]·4.2H2O phase formed for X = 0.4. This reaction for X = 0.4 was also possible for the dry process without methanol. In the case of X > 0.4, the peaks of the SrFe- complex were observed in the XRD pattern. The perovskite phase was directly formed by the thermal decomposition at a low temperature for the milled X = 0.4 complex.