ランタン-ストロンチウム-ガリウム-ニオブを主成分とする酸化物の分解法及び誘導結合プラズマ発光分光法による分析

This paper describes a dissolution method for La-Sr-Ga-Nb (LSGN) oxide samples, which are hardly decomposed by conventional acid treatments. The LSGN oxides are not dissolved in any acid solution and do not undergo fusion with alkaline reagents, such as Na2CO3. However, the sample can undergo fusion with Na2B4O7 powder. A sample (50 mg) was fused with 1 g of Na2B4O7 in a Pt crucible, whose inside wall was covered with pre-melted Na2B4O7 (1 g). The melted product was cooled and then dissolved with a mixture of 30 ml HNO3 (1 : 1), 2.5 ml H2O2, and 1 g tartaric acid. After the addition of 1.5 ml of H2O2 and 5 ml of an Y solution (5 mg/ml) as an internal standard, the solution was diluted to 100 ml and measured by inductively coupled plasma-optical emission spectrometry. Two samples having different chemical compositions were analyzed to yield each in good agreement with the analytical values between two individual measurements.