title: Effect of Bi doping on magnetoresistance in La(0.7-x) Bi(x)Sr0.3MnO3.
abstract: It is shown that upon increasing Bi content (x) in La(0.7-x)Bi(x)Sr0.3MnO3, the ground state changes from ferromagnetic metal (x = 0) to charge ordered antiferromagnetic insulator (x > 0.4). The x = 0.3 compound shows unusual magnetic and magnetoresistive properties: it shows hysteresis in magnetization as a function of temperature, field-induced metamagnetic transition in the paramagnetic state, and nearly 100% magnetoresistance. The magnetoresistance as a function of composition at microH = 5 T increases from 38% for x = 0.05 to 99.6% for x = 0.3 and then drops to 60% for x = 0.4. The unusual behavior of x = 0.3 composition is suggested to coexistence of short-range charge-ordered clusters and ferromagnetic domains. The field-induced melting of these charge-ordered clusters leads to large magnetoresistance effect.
authors: Department of Physics and NUS Nanoscience and Nanotechnology Initiative (NUSNNI), 2 Science Drive 3, Faculty of Science, National University of Singapore-117542, Singapore.
authors: S K
authors: SK
authors: Barik
authors: R
authors: R
authors: Mahendiran
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D017097:Electric Impedance; D007811:Lanthanum / Q000737:chemistry*; D008280:Magnetics; D017895:Manganese Compounds / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010087:Oxides / Q000737:chemistry*; D013324:Strontium / Q000737:chemistry*
chemical_list: D017895:Manganese Compounds; D010087:Oxides; C027424:manganese oxide; D007811:Lanthanum; D001729:Bismuth; D013324:Strontium