Effect of low level substitution of Sr�?�Ba on transport and magnetic behaviour of La0.67Ca0.33MnO3

Bulletin of materials science

K Porsezian³  B Munirathinam⁴  M Krishnaiah⁴  M Manivel Raja²  S Arumugam¹ 

[1] Department of Physics, Bharathidasan University, Tiruchirapalli 620 024, India$$Department of Physics, Bharathidasan University, Tiruchirapalli 620 024, IndiaDepartment of Physics, Bharathidasan University, Tiruchirapalli 620 024, India$$;Advanced Magnetics Group, Defence Metallurgical Research Laboratory, Hyderabad 500 058, India$$Advanced Magnetics Group, Defence Metallurgical Research Laboratory, Hyderabad 500 058, IndiaAdvanced Magnetics Group, Defence Metallurgical Research Laboratory, Hyderabad 500 058, India$$;Department of Physics, Pondicherry University, Puducherry 605 014, India$$Department of Physics, Pondicherry University, Puducherry 605 014, IndiaDepartment of Physics, Pondicherry University, Puducherry 605 014, India$$;Department of Physics, Sri Venkateswara University, Tirupati 517 502, India$$Department of Physics, Sri Venkateswara University, Tirupati 517 502, IndiaDepartment of Physics, Sri Venkateswara University, Tirupati 517 502, India$$

关键词: Ceramic;    solâ€�?�gel processes;    magnetic measurements;    electronic transport;    X-ray diffraction.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

In this paper we report the investigation of transition metal oxide compound, La_0.67Ca_0.25Sr_0.04Ba_0.04MnO₃ (LCSBMO), along with La_0.67Ca_0.33MnO₃ (LCMO), synthesized by solâ€�?�gel route under identical conditions. The effect of simultaneous low level substitution of large size ions such as Sr²⁺ and Ba²⁺ for Ca²⁺ ions on the electronic transport and magnetic susceptibility properties are analysed and compared apart from microstructure and lattice parameters. The temperature dependent electrical transport of the polycrystalline pellets of LCSBMO and LCMO when obeying the well studied law, ρ = ρ₀ + ρ₂ ð‘�??² for ð‘�?? < ð‘�??_MI, is observed to differ by more than 50% from the values of ρ₀ and ρ₂, with the former compound showing enhanced electrical conductivity than the latter. Similarly in fitting the adiabatic small polaron model for resistivity data of both the samples for ð‘�?? > ð‘�??_MI, the polaron activation energy is found to differ by about 11%. In addition, the temperature dependent a.c. magnetic susceptibility study of the compounds shows a shift of about 6% in the paramagnetic to ferromagnetic transition temperature (285 K for LCSBMO and 270 K for LCMO).

【 授权许可】

Unknown