Enhanced intergrain magnetoresistance in bulk Sr2FeMoO6 through controlled processing

Enhanced low field magnetoresistance (LFMR) values have been obtained in bulk Sr2FeMoO6 through controlled processing. MR values, R(H)/R(0) of ∼60% [(R(H)−R(H=0)/R(H=0)=40%] were achieved at 50 K, in 1 T, and R(H)/R(0)∼8% [(R(H)−R(H=0)/R(H=0)=92%] at 290 K, in 1 T. For a ∼1 μm starting particle size, the optimum sintering temperature was 1300 °C, 100 °C higher than normally used. The optimum sintering time in Ar/H2 was only 5 h, much shorter than normally used. The magnitude of the LFMR appears to depend strongly on grain boundary oxygen content, controlled through optimization of sintering temperature and time.

[1]  J. MacManus‐Driscoll,et al.  Highly aligned, spin polarized thin films of Sr2FeMoO6 by a chemical vapor process , 2002 .

[2]  M. Casanove,et al.  Magnetoresistive oxides: new developments and applications , 2002 .

[3]  M. T. Casais,et al.  The effect of substitutional mis-site disorder on the structural, magnetic and electronic transport properties of Sr2FeMoO6 double perovskites , 2002 .

[4]  J. Alonso,et al.  Origin of neutron magnetic scattering in antisite-disordered Sr 2 FeMoO 6 double perovskites , 2001, cond-mat/0111524.

[5]  M. Venkatesan,et al.  Enhanced magnetoresistance in Sr2FeMoO6 by combustion synthesis , 2002 .

[6]  J. Fontcuberta,et al.  Oxygen-induced grain boundary effects on magnetotransport properties of Sr 2 FeMoO 6 + δ , 2001 .

[7]  M. Bibes,et al.  Antisite defects and magnetoresistance in Sr2FeMoO6 double perovskite , 2001 .

[8]  F. Rivadulla,et al.  Magnetic and electric properties of Sr2FeMoO6 , 2001 .

[9]  M. Bibes,et al.  Cationic ordering control of magnetization in Sr2FeMoO6 double perovskite , 2000, cond-mat/0007248.

[10]  J. Goodenough,et al.  Enhancement of room temperature magnetoresistance in double perovskite ferrimagnets , 2000 .

[11]  M. Karppinen,et al.  Novel methods of synthesis and wet-chemicalredox analysis for magnetoresistive double-perovskite Sr2FeMoO6 − w , 2000 .

[12]  S. Wang,et al.  Enhanced intergrain tunneling magnetoresistance in double perovskite Sr2FeMoO6 polycrystals with nanometer-scale particles , 1999 .

[13]  Naoki Kobayashi,et al.  Continuous excitation of planetary free oscillations by atmospheric disturbances , 1998, Nature.