Title :
Intergranular tunneling magnetoresistance of mechanically alloyed (Cr-M)O2 powder compacts
Author :
Tsunoda, M. ; Sato, T. ; Zhang, Q. ; Jeyadevan, B. ; Takahashi, Masaharu
Author_Institution :
Dept. of Electron. Eng., Tohoku Univ., Sendai, Japan
Abstract :
The (Cr-M)O2 (M = V, Mn, Fe, Co) powder compacts are synthesized by mechanical grinding of CrO3 and Cr(OH)3 with the raw material of dopant ions followed by cold pressing. XRD, VSM and SQUID measurements are utilized to identify the ground products and to measure the magnetic properties of the powder compacts. The effect of dopant ions on the magnetotransport properties of CrO2 powder compacts in relation with their magnetic properties is studied at temperature range of 4.2-300 K with four-probe method under maximum applied field of 13 kOe. The behavior of each dopants on the temperature dependence of saturation magnetization, magnetoresistance ratio, and temperature dependence of electric resistivity of (Cr-M)O2 powders is investigated.
Keywords :
X-ray diffraction; chromium compounds; cobalt compounds; compaction; doping profiles; grinding; iron compounds; magnetisation; manganese compounds; mechanical alloying; powders; pressing; tunnelling magnetoresistance; vanadium compounds; (CrCo)O2; (CrFe)O2; (CrMn)O2; (CrV)O2; 4.2 to 300 K; SQUID measurements; VSM measurements; X-ray diffraction; cold pressing; dopant ions; electric resistivity; four-probe method; ground products; intergranular tunneling magnetoresistance; magnetoresistance ratio; magnetotransport; mechanical grinding; mechanically alloyed powder compacts; saturation magnetization; Iron; Magnetic properties; Powders; Pressing; Raw materials; SQUIDs; Saturation magnetization; Temperature dependence; Tunneling magnetoresistance; X-ray scattering;
Conference_Titel :
Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International
Print_ISBN :
0-7803-9009-1
DOI :
10.1109/INTMAG.2005.1463953
