Magneto-transport Properties of Gd-doped In2O3 Thin Films
- PDF / 625,069 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 59 Downloads / 217 Views
1032-I06-04
Magneto-transport Properties of Gd-doped In2O3 Thin Films R. K. Gupta1, D. Brown1, K. Ghosh1, S. R. Mishra2, and P. K. Kahol1 1 Department of Physics, Astronomy, and Materials Science, Missouri State University, Springfield, MO, 65897 2 Department of Physics, The University of Memphis, Memphis, TN, 38152 ABSTRACT Dilute Magnetic Semiconductors (DMS) are a rare group of promising materials that utilize both the electronic charge - a characteristic of semiconductor materials - and the electronic spin - a characteristic of magnetic materials. Oxide based DMS show promise of ferromagnetism (FM) at room temperature. It has been found that doping metal oxides such as ZnO, TiO2, and In2O3 with magnetic ions such as Fe, Co, Mn, and Cr produces DMS, which exhibit FM above room temperature. In2O3, a transparent opto-electronic material, is an interesting prospect for spintronics due to a unique combination of magnetic, electrical, and optical properties. High quality thin films of rare earth magnetic gadolinium (Gd) doped oxidebased DMS materials have been grown by pulsed laser deposition (PLD) technique on various substrates such as single crystal of sapphire (001) and quartz under suitable growth conditions of substrate temperature and oxygen pressure in the PLD chamber. The effect of rare earth magnetic doping on the structural and electro - magnetic properties of these films has been studied using Raman Spectroscopy, X-Ray Diffraction, Scanning Electron Microscopy, and Magneto - Transport. An X- ray diffraction study reveals that these films are single phase and highly oriented. Characteristic Raman peaks typical of indium oxide are observed at 496 and 627 cm-1. We have observed high magnetoresistance (~18 %) at a relatively small field of 1.3 Tesla for the films with 10 % gadolinium. A detailed study of temperature and magnetic field dependent resistivity, magnetoresistance, and Hall Effect will be presented.
INTRODUCTION Transparent conducting oxides (TCO) are widely used in opto-electronic devices such as light emitting diodes, photodetectors, touch panels, flat panel displays, and solar cells [1-3]. High electrical conductivity, high mobility, and good transparency are essential requirements for these devices [4-5]. According to the Drude model, optical transparency depends on the plasma frequency, which shifts to shorter wavelengths with higher carrier concentration [6]. To obtain high transparency and conductivity, one therefore needs to increase the mobility. Among the various TCO, indium oxide (In2O3) doped with tin is widely used because of its low electrical resistivity and high transparency [7]. But the mobility of these films is not very high (29 cm2/V.s). It is observed that doping of indium oxide with molybdenum instead of tin improves the carrier mobility (> 70 cm2/V.s) [6]. Titanium doping also improves the mobility of the indium oxide films. Hest et. al. [8] deposited titanium doped indium oxide by sputtering and observed a maximum mobility in their experiments of 83.3 cm2/V.s. In this commu
Data Loading...
