title: Role of Cu2+ ions substitution in magnetic and conductivity behavior of nano-CoFe2O4.
abstract: Cobalt copper ferrite nanopowders with composition Co1-xCuxFe2O4 (0.0≤x≤0.5) was synthesized by solution combustion method. The powder X-ray diffraction studies reveal the formation of single ferrite phase with particle size of ∼11-35 nm. Due to increase in electron density with in a material, X-ray density increase with increase of Cu2+ ions concentration. As Cu2+ ions concentration increases, saturation magnetization decreases from 38.5 to 26.7 emu g(-1). Further, the squareness ratio was found to be ∼0.31-0.46 which was well below the typical value 1, which indicates the existence of single domain isolated ferrimagnetic samples. The dielectric and electrical modulus was studied over a frequency range of 1 Hz to 1 MHz at room temperature using the complex impedance spectroscopy technique. Impedance plots showed only one semi-circle which corresponds to the contributions of grain boundaries. The lower values of dielectric loss at higher frequency region may be quite useful for high frequency applications such as microwave devices.
authors.affiliation: Prof. CNR Rao, Centre for Advanced Materials Research, Tumkur University, Tumkur 572 103, India; Department of Physics, SJB Institute of Technology, Bangalore 560 060, India; CMRTU, R.V. College of Engineering, Bangalore 560 059, India.
authors.forename: D M
authors.initials: DM
authors.lastname: Jnaneshwara
authors.affiliation: CMRTU, R.V. College of Engineering, Bangalore 560 059, India.
authors.forename: D N
authors.initials: DN
authors.lastname: Avadhani
authors.affiliation: Department of Physics, B.M.S. Institute of Technology, Bangalore 560 064, India.
authors.forename: B
authors.initials: B
authors.lastname: Daruka Prasad
authors.affiliation: Prof. CNR Rao, Centre for Advanced Materials Research, Tumkur University, Tumkur 572 103, India. Electronic address: bhushanvlc@gmail.com.
authors.forename: H
authors.initials: H
authors.lastname: Nagabhushana
authors.affiliation: Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054, India.
authors.forename: B M
authors.initials: BM
authors.lastname: Nagabhushana
authors.affiliation: Chhattisgarh Swami Vivekananda Technical University, North Park Avenue, Sector 8, Bhilai, Chhattisgarh 490 009, India.
authors.forename: S C
authors.initials: SC
authors.lastname: Sharma
authors.affiliation: Research Center, Department of Physics, East-West Institute of Technology, Bangalore 560 091, India. Electronic address: scphysics@gmail.com.
authors.forename: S C
authors.initials: SC
authors.lastname: Prashantha
authors.affiliation: Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India.
authors.forename: C
authors.initials: C
authors.lastname: Shivakumara
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D004553:Electric Conductivity; D017097:Electric Impedance; D005296:Ferrous Compounds / Q000737:chemistry*; D007477:Ions; D060328:Magnetic Phenomena; D053758:Nanoparticles / Q000737:chemistry*; D011208:Powders; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D005296:Ferrous Compounds; D007477:Ions; D011208:Powders; D003035:Cobalt; D003300:Copper
keywords: Dielectric loss; Grain boundary; Relaxation time; X-ray density