Colossal magnetoresistance in the layered chromium sulfide Cr2 S3-x (x=0.08)
Physical Review B - Condensed Matter and Materials Physics 64:13 (2001) 1324021-1324024
Abstract:
We report structural, magnetic, and magnetotransport properties of the two-dimensional chromium sulfide Cr2S2.92, which contains both Cr3+ and Cr2+ ions. Below its magnetic-ordering temperature (TN=118 K), Cr2S2.92 exhibits a weak spontaneous magnetization with a maximum around 90 K and a value of 0.013(4) μB per Cr ion at 5 K. The resistivity and magnetoresistance exhibit pronounced local maxima around TN (MR=48% in a field of 14 T). The magnetotransport properties are discussed in terms of magnetic-polaron formation.Chemically induced magnetism and magnetoresistance in La(0.8)Sr(1.2)Mn(0.6)Rh(0.4)O(4).
J Am Chem Soc 123:31 (2001) 7610-7615
Abstract:
It is shown by magnetometry and microSR spectroscopy that short-range magnetic interactions between the Mn cations in the nonmetallic K(2)NiF(4)-like phase La(0.8)Sr(1.2)Mn(0.6)Rh(0.4)O(4) become significant below approximately 200 K. Negative magnetoresistance (rho/rho(0) approximately 0.5 in 14 T at 108 K) is apparent below this temperature. Neutron diffraction has shown that an applied magnetic field of 5 T is sufficient to induce saturated (3.38(7)mu(B) per Mn) long-range ferromagnetic ordering of the atomic moments at 2 K, and that the induced ordering persists up to a temperature of 50 K in 5 T. Spin glass behavior is observed below 20 K in the absence of an applied field. The induced magnetic ordering is attributed to the subtle changes in band structure brought about by the external field, and to the controlling influence of Rh(3+) over the relative strength of competing magnetic exchange interactions.Two Modifications of Layered Cobaltous Terephthalate: Crystal Structures and Magnetic Properties
Journal of Solid State Chemistry 159:2 (2001) 343-351
A mu SR study of the CDW in TTF-TCNQ
SYNTHETIC MET 120:1-3 (2001) 997-998
Abstract:
The muon spin rotation (mu SR) technique is primarily a powerful probe of the magnetic properties of materials; but it is also possible to measure charge-density related effects using muon quadrupolar level crossing resonance (QLCR). We present the first study of a charge density wave (CDW) using mu SR in TTF-TCNQ. The CDW develops below the metal-insulator transition at 54 K and we study the evolution of the CDW as a function of temperature using the QLCR resonances of the nitrogen atoms on the TCNQ molecules as the probe.A quantum-mechanical model of quasi-one-dimensional conductors
SYNTHETIC MET 120:1-3 (2001) 1009-1010