Competing magnetic interactions and low temperature magnetic phase transitions in composite multiferroics. (19th August 2015)

• Record Type: Journal Article
• Authors: Borkar, Hitesh; Choudhary, R J; Singh, V N; Tomar, M; Gupta, Vinay; Kumar, Ashok
• Is Part Of: Materials research express. Volume 2:Number 8(2015)
• Publication Date: 2015-08-19
• Subjects: multiferroics -- composite -- ferroelectrics -- magnetics; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/2/8/086101
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: Novel magnetic properties and magnetic interactions in composite multiferroic oxides Pb[(Zr0.52 Ti0.48 )0.60 (Fe0.67 W0.33 ).40 ]O3 ]0.80 –[CoFe2 O4 ]0.20 (PZTFW–CFO) have been studied from 50 to 1000 Oe field cooled (FC) and zero field cooled (ZFC) probing conditions, and over a wide range of temperatures (4–350 K). Crystal structure analysis, surface morphology, and high resolution transmission electron microscopy images revealed the presence of two distinct phases, where micro- and nano-size spinel CFO were embedded in tetragonal PZTFW matrix and applied a significant built-in compressive strain (∼0.4–0.8%). Three distinct magnetic phase transitions were observed with the subtle effect of CFO magnetic phase on PZTFW magnetic phase transitions below the blocking temperature ( T B ). Temperature dependence magnetic property m ( T ) shows a clear evidence of spin freezing in magnetic order with lowering in thermal vibration. Chemical inhomogeneity and confinement of nanoscale ferrimagnetic phase in paramagnetic/antiferromagnetic matrix restrict the long range interaction of spin which in turn develop a giant spin frustration. A large divergence in the FC and ZFC data and broad hump in ZFC data near 200 (±10) K were observed which suggests that large magnetic anisotropy and short range order magnetic dipoles lead to the development of superparamagnetic states in composite.