Sol-gel synthesis, structural, optical and magnetic characterization of Ag3(2+x)PrxNb4-xO11+delta (0.0 <= x <= 1.0) nanoparticles

Abstract

In this work we have studied the optical and magnetic properties of sol-gel synthesized nanocrystalline Ag3(2+x)PrxNb4-xO11+delta (x = 0.0, 0.50 and 1.0; S1-S3) samples. The structural, morphological, optical and magnetic properties of the nanoparticle were investigated using X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray profile, optical absorbance spectroscopy, vibrating sample magnetometer and electron paramagnetic resonance spectroscopy. The X-ray diffraction results reveal the formation of single-phase monoclinic lattice structure with P2/m in all the samples. The optical absorption spectra indicates charge transfer from O2- to Nb5+ of niobium and H-3(4) to D-1(2), P-3(0), P-3(1) and P-3(2) of praseodymium (4f(2)) ions. Magnetic studies reveal that the samples exhibit ferromagnetism at room temperature. EPR lineshapes of the nanoparticles S1-S3 at 77 and 300 K show a broad unresolved isotropic lineshapes due to the relaxation process.