| 摘要 |
<p>PURPOSE:To measure the Curie point of oxide piezoelectric material with high reproducibility by matching the particle size of powder of oxide piezoelectric material to a narrow range of + or - specific mum in a range of specific mum. CONSTITUTION:An LiNbO3 crystal is, for example, pulverized by a mortar, and a sample having a particle size of 50-150mum is formed by a screen. Then, the sample is so pulverized as to align the particle size to a range of + or -10mum to form a sample with a screen having a nominal dimension of 63-75mum. A predetermined mg of this sample is filled in a platinum pan vessel 5. As reference substance alpha-alumina powder is introduced to a platinum pan vessel 5'. The vessels 5, 5' are covered, and placed on a heat sensitive plate 4 of a furnace 3. A heating block 2 is coated with a cover 7, a heater 1 is energized to be gradually raised at its temperature. Their temperatures are measured by thermocouples 6, 6', a peak top temperature of a heat absorption peak of the Curie point of the sample is read, and used as a Curie point. Even if the same sample is measured plural times by this method, measuring reproducibility can be improved up to its standard deviation sigman-1 = about 0.11.</p> |
