Title :
ITC technique as tool to monitor a new phase nucleation in LiF:Ti single crystals
Author :
Capelletti, Rosanna ; Foldvari, Istvan ; Mora, Chrlo ; Prato, Stefano
Author_Institution :
Dept. of Phys., Parma Univ., Italy
Abstract :
Thermal treatment of LiF:Ti3+ at temperatures close to the melting point in a moist atmosphere causes the growth of new phase occlusions. Optical and electron microscopy and X-ray diffraction have shown that they are parallelepipeds and cubes of a face-centered-cubic phase coherent with the host matrix. ITC (ionic thermoconductivity) spectra support that the crystal behaves as an inhomogeneous dielectric; in fact the occlusion growth is accompanied by the appearance of new ITC bands at the expense of the band due to the reorientation of dipoles built by Ti3+ and two cation vacancies. The nucleation kinetics has been studied in this way and the Maxwell-Wagner-Sillars model was applied to interpret the ITC spectra
Keywords :
X-ray diffraction examination of materials; electrets; electron microscope examination of materials; ionic conduction in solids; lithium compounds; nucleation; titanium; ITC technique; LiF:Ti single crystals; Maxwell-Wagner-Sillars model; X-ray diffraction; cubes; electret; electron microscopy; face-centered-cubic phase; ionic thermoconductivity; melting point; moist atmosphere; new phase occlusions; nucleation kinetics; parallelepipeds; phase nucleation; Atmosphere; Dielectrics; Electron microscopy; Electron optics; Kinetic theory; Monitoring; Optical diffraction; Optical microscopy; Temperature; X-ray diffraction;
Conference_Titel :
Electrets, 1991. (ISE 7) Proceedings., 7th International Symposium on (Cat. No.91CH3029-6)
Conference_Location :
Berlin
Print_ISBN :
0-7803-0112-9
DOI :
10.1109/ISE.1991.167270
