Inductively coupled plasma—atomic emission spectrometry (ICP-AES): an analytical technique for the chemical characterization of perovskite ceramic semiconductors

The possibilities of inductively coupled plasma-atomic emission spectrometry (ICP-AES) for the chemical characterization (dopants, impurities, and macroconstituents) of perovskite ceramic semiconductors (PTC thermistors, varistors, manganites, cobaltites) are shown. The dissolution of the samples is achieved by five methods: (a) decomposition with HCl in a Teflon-lined pressure vessel, (b) decomposition with HF + H₂SO₄ in a Teflon-lined pressure vessel, (c) decomposition with (NH₄)₂SO₄ + H₂SO₄ in a platinum dish, (d) fusion with Na₂CO₃ + Na₂B₄O₇ in a platinum crucible, (e) fusion with Li₂B₄O₇ in a graphite crucible. The spectral interferences and the inter-element effects are studied and corrected. The detection limits are comprised, approximately, between 0.00001% and 0.1%. High sensitivity and good precision are attained.