Ferromagnetism and transport properties of Fe-doped reduced-rutile TiO2−δ thin films

Abstract

We have investigated Fe x Ti 1Ϫx O 2Ϫ␦ (xϭ0.02, 0.06, and 0.08͒ thin films grown on ␣-Al 2 O 3 substrates by pulsed-laser deposition. X-ray diffraction results indicate that the films are single phase and of reduced-rutile type. Detailed microstructural observations reveal no measurable magnetic impurities in the films. Vibrating sample magnetometer measurements show the films are ferromagnetic at room temperature with coercivity ranging from 340 to 770 Oe. The temperature dependence of the resistivity shows nearly metallic behavior at room temperature but semiconducting behavior at lower temperatures. The extraordinary Hall effect with coercivities similar to those in magnetic hysteresis curves was observed at room temperature. The carriers are p type with a carrier density of about 10 22 /cm 3 .

Magnetic oxide semiconductors

“…V-doped anatase TiO 2 was reported to be ferromagnetic at room temperature [129]. Fe-doped rutile TiO 2 was reported to be ferromagnetic over room temperature [130][131][132][133] and to show anomalous Hall effect at room temperature [131,132]. Fe-doped anatase TiO 2 was reported to be ferromagnetic at room temperature [134,135].…”

Exploiting magnetic properties of Fe doping in zirconia

“…Recently a new class of DMS has been investigated, namely DMS based on high-k oxides, i.e. dilute magnetic oxides (DMO), after the experimental evidence of room temperature magnetism in transition metals (TMs) doped zirconia [5,6,7,8] (ZrO 2 ), hafnia [9,10] (Hf O 2 ), and titania [11,12] (T iO 2 ) and the theoretical prediction of high T c in TMs doped ZrO 2 [13,14].…”

Structural and magnetic properties of (In1−xFex)2O3 (0.0⩽x⩽0.25) system: Prepared by gel combustion method

“…[2][3][4][5][6][7][8][9][10] For practical spintronic applications DMS with Curie temperature, Tc, above RT are required. Many promising oxides like TiO 2 , ZnO and SnO 2 and III-V semiconductor GaN doped with transition metal ions have been reported to exhibit ferromagnetic behavior near or above room temperature, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] but the origin of ferromagnetism in these systems is poorly understood. Oxide systems based on host semiconductor with high solubility of magnetic ions are highly desirable to form thermodynamically stable magnetic semiconductors.…”