3 research outputs found
Determination of Mg composition in MgâZnâËâO alloy: Validity of Vegardâs law
Vegardâs law and inductively coupled plasma atomic emission spectrometry were employed to determine the Mg composition in MgâZnâËâO layers deposited on 6HâSiC substrates. With the increase of Mg composition in MgâZnâËâO layers, the c-axis length decreased by 5.2048â0.072x, while the a-axis length increased to 3.2491+0.047x. The lattice constants estimated by Vegardâs law and a theoretical model exhibited an uncertainty of âŒ3% that has been attributed to the âŒ2% lattice misfit in the MgOâZnO materials system. Localized exciton peaks of MgâZnâËâO alloy in photoluminescence(PL) measurements disappeared completely, while the neutral donor-acceptor pair and 1-longitudinal optical-phonon energies decreased rapidly with the increase of Mg composition. These PL data do not comply with Vegardâs law. The asymmetric behavior in the MgâZnâËâO alloy is the subject of locally disordered Mg potential fluctuations and an artifact of the cMgO and aMgO lengths calculated theoretically.This work was supported in part by the Special Postdoctoral
Research Fellowship Program, Photodynamics Research
Center, The Institute of Physical and Chemical Research
RIKEN, Japan