Preparation and Effect of Oxygen Annealing on the Electrical and Magnetic Properties of Epitaxial (0001) Zn_(1-x)Co_xO Thin Films  

作　　者：罗嗣俊 张联盟 WANG Chuanbin ZHOU Xuan SHEN Qiang 

机构地区：[1]State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2013年第5期893-897,共5页武汉理工大学学报（材料科学英文版）

基　　金：Funded by New Century Excellent Talents in University(No.NCET-10-0662);International Science and Technology Cooperation Project of Hubei Province(No.2010BFA017);International Science&Technology Cooperation Program of China(No.2011DFA52650)

摘　　要：Epitaxial （0001）-oriented Zn1-xCoxO （x= 0.01, 0.05 and 0.1） thin films were grown on c-sapphire substrates by pulsed laser deposition. The XRD analysis, optical transmittance and XPS measurements revealed that the Co2＋ substituted Zn2＋ ions were incorporated into the lattice of ZnO in Zn1-xCoxO thin films. The electrical properties measurements revealed that the Co concentration had a non- monotonic influence on the electrical properties of the Zn1-xCoxO thin films due to the defects resulted from imperfections induced by Co substitution. The resistivity remarkably increased and the carrier concentration remarkably decreased in Zn1-x CoxO thin films after oxygen annealing at 600 ℃ under 15 Pa O2 pressure for 60 mins. Room-temperature ferromagnetic was observed and the ferromagnetic Co amount was smaller than the nominal Co concentration for Zn1-xCoxO samples before oxygen annealing. After oxygen annealing, the Zn1-x CoxO thin films exhibited paramagnetic behavior. It is suggested that the room-temperature ferromagnetic ofZn1-x CoxO thin films may attribute to defects or carriers induced mechanism.Epitaxial （0001）-oriented Zn1-xCoxO （x= 0.01, 0.05 and 0.1） thin films were grown on c-sapphire substrates by pulsed laser deposition. The XRD analysis, optical transmittance and XPS measurements revealed that the Co2＋ substituted Zn2＋ ions were incorporated into the lattice of ZnO in Zn1-xCoxO thin films. The electrical properties measurements revealed that the Co concentration had a non- monotonic influence on the electrical properties of the Zn1-xCoxO thin films due to the defects resulted from imperfections induced by Co substitution. The resistivity remarkably increased and the carrier concentration remarkably decreased in Zn1-x CoxO thin films after oxygen annealing at 600 ℃ under 15 Pa O2 pressure for 60 mins. Room-temperature ferromagnetic was observed and the ferromagnetic Co amount was smaller than the nominal Co concentration for Zn1-xCoxO samples before oxygen annealing. After oxygen annealing, the Zn1-x CoxO thin films exhibited paramagnetic behavior. It is suggested that the room-temperature ferromagnetic ofZn1-x CoxO thin films may attribute to defects or carriers induced mechanism.

关 键 词：Zn1-xCoxO thin film pulsed laser deposition oxygen annealing electrical properties magnetic property 

分 类 号：TN304.055[电子电信—物理电子学]