Thermal stability of the OH-Li complex in hydrothermally grown single crystalline ZnO

The thermal stability of the prominent 3577 cm(-1) infrared absorption band in ZnO, assigned to an O-H stretch mode adjacent to a Li atom on Zn site (Li(Zn)), is studied. Employing slow sample cooling after annealing, the 3577 cm(-1) peak remains at temperatures <= 1250 degrees C, consistent with previous reports. However, if the samples are cooled rapidly by quenching, the peak disappears after annealing for 1 h at 650 degrees C. A dissociation energy of less than 2.5 eV is deduced for the OH-Li(Zn) complex and the apparent high thermal stability after slow cooling is attributed to efficient recapturing of H by Li(Zn). Moreover, deuterium (D) is found to replace hydrogen in OH-Li(Zn) after 1 h at 700 degrees C in D(2) gas. (C) 2010 American Institute of Physics. [doi:10.1063/1.3522886]