Magnetic and magnetotransport properties in copper and iron co-doped bulk indium oxide and indium tin oxide.

• Main Author: Ho, Hui Wen.
• Other Authors: Wang Lan
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Materials::Magnetic materials
• Online Access: http://hdl.handle.net/10356/14929
• Institution: Nanyang Technological University

Spin based electronics, commonly known as “spintronics”, is expanding its functionalities of microelectronic devices by trying to add on its ability to manipulate the carrier's spin, in addition to or instead of its charge. This in turn, led us to the development of magnetic semiconductors. Dilute magnetic semiconductor (DMS) is a class of magnetic semiconductor whereby a small amount of the ions are substitutionally replaced by magnetic ions. The interaction between the spin of the dopant and the carriers in the semiconductor host is expected to bring about ferromagnetic order in the materials. Search for novel DMS candidates is driven by the requirement of having high Curie temperature. In this work, we have investigated the structural, magnetic and transport properties of (In0.85-xFe0.15Cux)2O3 (IFCO) and (In0.80-xSn0.05Fe0.15Cux)2O3 (ISFCO) compounds with x = 0, 0.02, and 0.05 which may be a candidate for DMS. All studied samples show clear room temperature ferromagnetism and saturated magnetic moment decreases with increasing Copper-doping. Detailed analysis about its intrinsic ferromagnetism is being discussed. A crossover from semiconducting to metallic transport behavior is observed in IFCO samples, whereas only semiconducting behavior is found in ISFCO. Low temperature resistivity decreases with increasing Copper-doping level due to increase in electron concentration. Positive magnetoresistance and Anomalous Hall Effect (AHE) is observed in IFCO at 5 K and 300 K. No magnetoresistance and AHE is found in ISFCO compounds.