An explicit and novel structure,lattice dynamics,and photoemission of La-doped nanocrystalline SrZrO_(3) perovskite  

作　　者：Kamilia Sedeek Nahed Makram Hanan Hantour Taghreed Zaghloul Amer Shimaa Ali Said 

机构地区：[1]Nano-Materials Laboratory,Physics Department,Faculty of Science,Al-Azhar University,Nasr City,Cairo 11751,Egypt [2]Physics Department,Faculty of Science,Al-Azhar University,Nasr City,Cairo 11751,Egypt

出　　处：《Rare Metals》2021年第1期105-112,共8页稀有金属（英文版）

基　　金：the Grants Commission of Al-Azhar University,Cairo,Egypt for supporting this work。

摘　　要：As no complete and comprehensive studies have been previously reported for La-doped nanocrystalline SrZrO_(3)(SZO),we researched herein a detailed investigation for pure and La-doped samples.A modified solid-state reaction process,including successive cycles of milling and sintering at high temperature,was followed to produce SZO and Sr_(0.9)La_(0.1)ZrO_(3)(SLZO)powdered ingots.Rietveld analysis of X-ray diffractometer data predicts that the two samples exhibit orthorhombic structure with an increase in crystallite size by~25%for doped sample.A great reduction in Raman modes intensity(~60%)and an annihilation of several vibration modes were detected using Raman spectroscopy.The degree of ordering on the B-site was recorded to be higher in La-doped sample.According to ultraviolet-visible(UV-Vis)absorption,a decrease in the optical gap width(E_(g))from 4.40 eV to 4.21 eV was achieved by La incorporation due to the presence of additional defect states such as oxygen and Sr vacancies at the band edge.The process of electron-hole recombination was studied using photoluminescence(PL)spectroscopy.Deconvolution of PL spectra yielded four emission bands:one green band,one blue band,and two violet bands.Highly intense violet emission atλ=393 nm approximately five times greater than that detected for pure SZO is realized as La^(3+)substitutes for Sr^(2+).Such property nominates SLZO for technological applications requiring highly intense violet emission,e.g.,light-emitting diodes.

关 键 词：Orthorhombic perovskite structure Lattice dynamics Diffused reflectance Photoluminescence Highly intense violet emission 

分 类 号：TM911.4[电气工程—电力电子与电力传动] TB383.1[一般工业技术—材料科学与工程]