NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2014, 5 (6), P. 843–848
SYNTHESIS AND STUDIES ROOM TEMPERATURE CONDUCTIVITY, DIELECTRIC ANALYSIS OF LaF3 NANOCRYSTALS
Sidheshwar G. Gaurkhede – Department of Physics, Bhavan’s College of ASC, Andheri (W) Mumbai-400058. India; email@example.com
Lanthanum fluoride (LaF3) was synthesized using LaCl3 and NH4F as starting materials in deionized water as solvent via a microwavea-ssisted technique. The structure of LaF3 nanocrystals, analyzed by XRD and TEM, was found to be hexagonal with an average crystalline particle size of 20 nm (JCPDS standard card (320483) of pure hexagonal LaF3 crystals). The resistivity and conductivity at room temperature for LaF3 was verified and found to depend on the applied DC field. At an applied voltage of 20 V/cm – 30 V/cm, the resistivity and conductivity changes rapidly due to the liberation of extra fluoride F- ions, whereas the conductivity of LaF3 nanocrystals depends upon temperature. The variation of dielectric constant (ε’) and dielectric loss (ε”) with applied frequency shows normal dielectric behavior, attributable to the space charge formation. The observed peak in the plot of tangent loss (tan δ) vs. log F around 2.6 KHz can be attributed to interface charge relaxation at the grain boundaries.
Keywords: Microwave radiation, Hexagonal shape, X-ray diffraction, Dielectric materials.
PACS 61.05.cp, 77.22.d