Dielectric Anomalies and Competing Magnetic Interactions in NiFe2O4-PMN-PT Nanocomposite Materials

K. Kamala Bharathi, Tripta Parida, Hanuma Kumar Dara, K. Ramesh Kumar, André M. Strydom, M. Sarathbavan, K. Ramamurthi

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

We report on dielectric anomalies, competing magnetic interactions and relaxor ferroelectric behaviors of xPMN-PT-(1 - x)NiFe2O4 (x = 0.2 and 0.4) nanocomposites. The crystal structure and surface morphology of the pure and composite nanomaterials were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Phase formation and purity of the NiFe2O4, PMN-PT and the composites were confirmed from XRD measurements. Uniformly distributed nanoparticles and nanowires and the presence of Ni, Fe, O, Pb, Nb, Mg, and Ti in NiFe2O4 and PMN-PT are confirmed from FESEM and energy dispersive X-ray (EDX) measurements. Structural disordering due to phase transition around 453 K in both composites was examined from temperature variation Raman studies. Magnetization measurements at room temperature and at 40 K, zero field cooled (ZFC) and field cooled (FC) magnetization measurements for both composites were carried out from 2 to 350 K. Competing magnetic interaction and spin glass behaviors were confirmed from ZFC and FC measurements. Random distribution of spins related with different particle size in both composites was confirmed from the distribution function associated with magnetocrystalline anisotropy energy barrier. Frequency (1 kHz to 40 MHz) and temperature (room temperature to 553 K) dependent dielectric measurements reveal the existence of dielectric relaxation behavior, dielectric anomalies and relaxor ferroelectric nature of both composites. Analysis of temperature dependent dielectric constant with modified Curie-Weiss law indicates the diffusion constant value of 1.8 and 1.5 for x = 0.2 and 0.4 composites respectively, clearly indicating the diffusive nature of the transitions and highly disordered nature of the relaxor ferroelectrics.

Original languageEnglish
Pages (from-to)880-887
Number of pages8
JournalJournal of Physical Chemistry C
Volume122
Issue number1
DOIs
Publication statusPublished - 11 Jan 2018

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • General Energy
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

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