【摘要】 钛酸钴晶体是重要的化工、电子材料,纳米COTiO₃因其表面效应、晶场效应、量子尺寸效应而具有重要的实用价值和研究价值。作者利用光声光谱技术对不同颗粒尺寸的纳米COTiO₃粉末进行了研究。结果表明,纳米CoTiO₃粉末随温度升高颗粒长大,从紫外可见光到近红外范围（350nm～1200nm）的光声光谱上出现了三个吸收肩带,研究结果表明,它们与自由激子、束缚激子和缺陷附加能级的电子跃迁有关,其变化趋势强烈地依赖于颗粒度的大小。更多还原

【Abstract】 Cobalt titanate is important as chemical and electric materials. Nanoscaled CoTiO₃ has attractive properties on surface effect, crystal field effect and quantum effect. It raises an intensive study on the fundamental properties or important applications of the materials. Photoacoustic spectroscopy has been used to study various sizes of nanoscaled CoTiO₃ powders. Three absorption bands （or shoulders） are observed from ultraviolet to near-infrared （350nm～1200nm） in the Photoacoustic spectra. Analyses indicate that they cause the transitions of free excitons, bound excitons and electronic transition of additional energy levels caused by defects. The variational tendency strongly depends on the grain sizes.更多还原