Correlation between lattice strain and magnetic behavior in non-magnetic Ca substituted nano-crystalline cobalt ferrite. Issue 6 (1st May 2016)

• Record Type: Journal Article
• Authors: Kumar, Rajnish; Kar, Manoranjan
• Is Part Of: Ceramics international. Volume 42:Issue 6(2016)
• Page Start: 6640
• Page End: 6647
• Publication Date: 2016-05-01
• Subjects: Spinel ferrite -- Magnetocrystalline anisotropy -- Rietveld -- Arrott plot; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2016.01.007
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Magnetic nanoparticles of calcium (Ca)-substituted cobalt ferrite i.e. Co1− x Ca x Fe2 O4 ( x =0.00, 0.01, 0.015, 0.02, 0.05, 0.1, and 0.15) have been synthesized by the citric acid modified sol–gel method. X-ray powder diffraction (XRD)patterns confirm the formation of spinel phase. The particle size decreases with the Ca concentration. The Rietveld refinement of XRD patterns using the space group – Fd 3 ̅ m shows monotonically increasing of lattice parameter with the increasing concentration of Ca. The FT-IR spectrum recorded in the range of 325–1000 cm −1 and Raman spectrum obtained in the range of 88–800 cm −1 shows the formation of spinel phase belonging to Fd 3 ̅ m space group supporting structural analysis from XRD patterns. Magnetocrystalline anisotropy has been obtained using "Law of Approach (LA) to Saturation magnetization". Saturation magnetization and remnant magnetization is maximum for 1% Ca substitution which could be due to strain mediated magnetism. However these magnetic properties decrease with the Ca substitution for the percentage above 1%. It could be due to decrease of magnetic exchange interaction in the sample. A correlation between magnetic behavior and lattice strain has been established in non-magnetic Ca substituted nano-crystalline cobalt ferrite. In order to investigate the ferromagnetic nature of the sample, Arrott plot analysis has been carried out. Difference in saturation magnetization obtained from LA to saturation and Arrott plot analysis gives the qualitative information about the influence of lattice strain on saturation magnetization.