Abstract Copper vanadate (CV) and manganese
vanadate (MV) exhibit magnetic and optical properties
that have drawn the attention. Due to CV polymorphism
and phase multiplicity, CV is common to
exist as mixed phases. In this study, nanostructures of
mixed-phase CVs mixed with MV were synthesized
hydrothermally followed by calcination at 400 °C,
with Mn mole fractions 0.0, 0.4, 0.6, 1.0. The uncalcined
and calcined Mn-Cu vanadates (MCVs) were
investigated by XRD, SEM, TEM, FT-IR, EDX, ICPAES,
TGA, DTA, DSC, BET, XPS, and VSM. XRD
analysis shows co-existence of multi-phase CVs with
MnV2O6
and V oxides. Electron micrographs show
nanostructures of multiple morphologies (rods, cubes,
sheets, and irregular). As Mn content increased in the
MCVs, their thermal stability increased, optical bandgap
(
Eg) declined from 2.46 to 1.60 eV, and magnetism
diverted from the superparamagnetic-like to
paramagnetic (Hc from 1362 to 69 G and Mr/Ms from 0.430 to 0.003). Magnetism parameters of calcined
MCVs were more labile to Mn content variation compared
to the uncalcined MCV counterparts. |
