Sol-Gel Synthesis of Some Rare Earth Cuprates RE2CuO4, (RE = La, Eu and Nd).

Abstract

Two samples of rare earth cuprates, RE₂CuO₄ (RE =La,
Eu, Nd) were prepared by using sol-gel method. The first
sample was prepared by mixing RECl₃ and CuCl₂ with molar
ratio 1:1 in presence of ethylene oxide gas as gelating agent.
The product was dried at 120 °C. The second one was prepared
from RECl₃ and CuCl₂ and using citric acid and ethylene glycol
for gelation with molar ratio 1:1:10:40. The product was dried
at 130 °C to give a gel form of RE₂CuO₄.  The gel was converted
to powder by heating at 350 °C. The produced samples were
characterized by XRD, IR, thermal analysis and SEM. The
results indicate that RE₂CuO₄ in a very fine particle size was
formed.  The analysis of XRD pattern showed that a single
phase of RE₂CuO₄ was formed by using the first method while
a residual of the precursor material was appeared on using
the second method. The electrical conductivity (O' ) of the produced
samples were measured between 25-300 °C after sintering
at 850 °C for 2 h. The results of measurements indicate that
all the produced samples behave as semiconductor materials
where the value of electrical conductivity (O' ) increased with
temperature.