Effect of La doping on optical and electrical transport properties of nanocrystalline YCrO3

• The dc conductivity of the samples increases with increasing La concentration.
• A linear variation has been observed in S-T curve.
• Band gap decreases with the increase of La concentration due to creation of mid gap.
• The activation energies decrease with increasing doping percentage.
• A relaxation peak has been observed in M//(f)−TM//(f)−T curve.

In this work we have reported the synthesis and characterization of La doped YCrO3 nanoparticles following sol-gel method. The optical band gap of the investigated samples decreases with the increase of doping content. Photoluminescence spectra show distinct red light emission in the visible range around 630 nm. Dielectric permittivity is measured within the temperature range 298 K–523 K and in the frequency range 20 Hz – 1 MHz following the power law ε'(f)∝Tpε'(f)∝Tp, which shows that the temperature exponent p increases with the decreasing frequency and its values varies from 11.4 to 17 for 1 MHz to 100 KHz frequency variation. The ac impedance analysis shows that grain boundary contribution is dominating over grain contribution. The dc conductivity of the investigated samples follows semiconductor behavior. The analysis of both the dc and ac conductivity shows that the activation energy decreases and the conductivity increases with the increase of doping concentration which is very much important for its application as interconnect material in Solid Oxide Fuel Cells (SOFCs).

A relaxation peak has been noticed in M//(f)−fM//(f)−f curve which is accompanied with the step like transition in M/(f)−fM/(f)−f which is shifting towards high frequency side with the increase of temperature, reveals the hopping type conduction mechanism.Figure optionsDownload as PowerPoint slide