Solubility of lanthanum in strontium titanate in oxygen-rich atmospheres

摘要: Perovskite (ABO3)-type lanthanum substituted strontium titanate ceramics (lanthanum content x), which had been sintered in pure oxygen at 1400 °C, were investigated from x = 0 up to 0.6 by light optical and scanning electron microscopic means conjunction with X-ray analysis, diffraction, pyconometry order determine the mechanism being responsible for compensation of electronic excess charge resulting "donor" lanthanum. A vacancy was observed contents 0.3. Above 0.4 titanium vacancies occur additionally but their concentration remains negligible compared predominating vacancies. No indication a solubility limit 0.4, as stated former works observed. At 0.5 lattice structure found be slightly distorted, tetragonally orthorhombically, respectively. The parameter obeys Vegard’s law end member La2/3□1/3TiO3 (□: vacant site). These results completely confirmed pycnometry data.