skip to main content

SciTech ConnectSciTech Connect

Title: Optical demagnetization in defect-mediated ferromagnetic ZnO:Cu films

Optical demagnetization effect has been observed in a defect-rich ZnO:Cu film. Phenomenally, UV illumination can effectively quench dual-donor oxygen vacancy (V{sub O}) and interstitial zinc (Zn{sub i}) mediated magnetic ordering (90% loss) with carrier recapture in ionized Zn{sub i} (Zn{sub i}{sup 2+} rather than Zn{sub i}{sup +}) traps. The involvement of carriers by means of metal Zn vapor annealing provides a bound carrier related magnetic scenario, stressing a more significant place of bound carrier rather than free carrier. Using light correlated electron spin resonance and magnetic measurements, the magnetic “on” and “off” state can be continuously manipulated via UV light, which is explained by the reversible process of [Cu{sub s}{sup +}/Cu{sub s}{sup 2+}] + Zn{sub i}{sup 2+} ↔ [Cu{sub s}{sup +}, h] + Zn{sub i}{sup +} (s and h denote the substitutional Cu ions on Zn sites in ZnO lattice and hole carrier, respectively). A slow charge-transfer process (∼15 μs) from Zn{sub i}{sup +} bound carriers to [Cu{sub s}{sup +}, h] states determines the unexpected optical demagnetization, well corresponding to control experiments.
Authors:
; ; ;  [1]
  1. State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027 (China)
Publication Date:
OSTI Identifier:
22283192
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; CHARGE CARRIERS; COPPER IONS; DEMAGNETIZATION; ELECTRON CORRELATION; ELECTRON SPIN RESONANCE; FERROMAGNETIC MATERIALS; FERROMAGNETISM; MAGNETIZATION; STRESSES; ULTRAVIOLET RADIATION; VACANCIES; VISIBLE RADIATION; ZINC; ZINC OXIDES