Near room temperature magnetodielectric consequence in (Li, Ti) doped NiO ceramic

Journal Article · Thu Apr 07 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4945318· OSTI ID:22594548

Rayaprol, S.; Kaushik, S. D. ^[1]; Chatterjee, S. ^[2]; Bhattacharya, S. ^[3]; Jana, P. K. ^[4]

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1. UGC-DAE Consortium for Scientific Research, Mumbai Centre, Bhabha Atomic Research Centre Campus, Trombay, Mumbai 400 085 (India)
2. UGC-DAE Consortium for Scientific Research, Kolkata Centre, Sector III, LB-8, Salt Lake, Kolkata 700 098 (India)
3. Technical Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)
4. Deshabandhu Vidyapith (H. S.), N. N. Road, Kolkata 700011 (India)

In the quest for high-k dielectrics with decent magnetodielectric (MD) response, ball-milled processed (Li, Ti) doped NiO ceramics have been evaluated by various experimental techniques. Magnetic properties in these ceramics manifest with a pronounced anomaly appearing at ∼260 K, suggesting ferrimagnetic phase (related to cluster magnetism) and co-existence with a glassy-like antiferromagnetic phase at ∼7 K. Room temperature neutron diffraction pattern shows the existence of short-range magnetic correlations. In the magnetically ordered state below 250 K, the magnetic structure is found to be phase coexistence of G-type antiferromagnet and ferrimagnet. Impedance spectroscopy measurements over a wide temperature range can be perfectly described with appropriate microstructural model (internal barrier layer capacitor), based on domain and domain boundary relaxations, justifying the enhancement of the dielectric response. The low-temperature (T < 100 K) dielectric relaxation is polaronic in nature, associated with the charge ordering of a mixed valence states of Ti ions (co-existence of Ti{sup 3+} and Ti{sup 4+}). Finally, our investigations in external magnetic fields up to 15 T reveal the occurrence of negative MD effect near room temperature. This intriguing intrinsic feature has been understood by the mechanism of charge-hopping-mediated MD effects.

• OSTI ID: 22594548
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 13; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANTIFERROMAGNETISM
CAPACITORS
CERAMICS
DIELECTRIC MATERIALS
DOPED MATERIALS
IMPEDANCE
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MICROSTRUCTURE
NEUTRON DIFFRACTION
NEUTRON TEMPERATURE
NICKEL OXIDES
RELAXATION
SPECTROSCOPY
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TITANIUM IONS
VALENCE