Low temperature ferromagnetic behavior and temperature dependent anomalous dielectric relaxation of Zn0.90Ni0.05Mn0.05O diluted magnetic semiconductor

• Published in: Journal of materials science. Materials in electronics Vol. 29; no. 10; pp. 8244 - 8257
• Main Authors: Ahmed, Raju, Siddique, Anwar, Moslehuddin, A. S. M., Mahmood, Z. H., Hossain, A. K. M. Akther
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-05-2018; Springer Nature B.V
• Subjects: Atomic force microscopy; Atomic structure; Characterization and Evaluation of Materials; Chemistry and Materials Science; Coercivity; Curie temperature; Dielectric properties; Dielectric relaxation; Dilution; Ferromagnetism; Low temperature; Magnetic permeability; Magnetic properties; Magnetization; Materials Science; Microscopy; Optical and Electronic Materials; Remanence; Scanning electron microscopy; Tangents; Temperature; Temperature dependence; Wurtzite; X-ray diffraction
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-018-8831-8

We report structural, magnetic and temperature dependent dielectric properties of diluted magnetic semiconductor Zn
0.90
Ni
0.05
Mn
0.05
O prepared by solid state reaction technique. X-ray diffraction analysis revealed formation of single phase hexagonal wurtzite structure. Scanning electron microscopy and atomic force microscopy images indicated increase in grain size and roughness respectively with increasing sintering temperature. Field dependent DC magnetization at low temperature exhibited ferromagnetic ordering with coercivity ~ 6 × 10
4
 A/m and remanence ~ 17 A/m. Complex initial permeability values were found to be positive for the measurement frequency range (1 kHz–120 MHz) with a relaxation at lower frequency. Temperature dependent DC magnetization and AC susceptibility followed curie law with curie temperature below 65 K. Temperature dependent dielectric constants (
) and loss tangents (
) measured for selected frequencies were found to be an increasing function of temperature and decreasing function of frequency. AC conductivity (
) values were found to be an increasing function of frequency and temperature. Clear signatures of relaxations were observed in
and
for temperatures above 200 °C.