Room Temperature Structural, Electrical and Dielectric Studies of Ce3+, Pr3+ Doped Hexagonal LaF3 Nanoparticles

Water soluble LaF3: Ce3+, Pr3+ (LFCP) nanocrystals have been synthesized using microwave assisted process. Using de-ionized water (DW) and methanol (M) as solvents nano discs and nano rods with hexagonal geometry were obtained. In agreement with the X-ray diffraction (XRD), Transmission electron microscope (TEM) confirms the average crystalline size of the particles is 20 nm which is close to the JCPDS standard card number (32-0483). The functional groups of the synthesized nanoparticles were confirmed by comparative Fourier transform infra red (FTIR) and FT-Raman spectra. Thermo gravimetric analysis (TGA/ DTA) from 100 0C to 900 0C are attributable to the initial removal of water molecules / semi organic ligands shows formation and related internal crystal structure adjustments. The excitation peak was found to be at 254 nm which exhibiting blue up conversion fluorescence (459 nm). The ionic conductivity at room temperature is found to of order of 10 -6 Scm-1 corresponding to resistivity of order of 105 Ωcm with higher magnitude in DW based nanocrystals. Dielectric constant and dielectric loss show normal dielectric behavior in frequency range of 100 Hz - 5 MHz with their values falling drastically at low frequencies indicating good optical quality nanocrystals. Dielectric studies involvement of the real part of dielectric constant in the process of polarization.