Abstract:
It is widely accepted that there is Griffiths phase (GP) present
in the paramagnetic phase in doped manganites. We studied
the effect of quenched disorder on the region of GP in connection
with the temperature dependence of the line width
(ΔH) of the electron paramagnetic resonance (EPR) in
La0.67–2xNd2xCa0.33–xSrxMnO3 (x = 0, 0.1, 0.15, 0.2 and 0.25).
With this approach it is found that ΔH(T), the minimum in
the line width (ΔHmin) and Tmin are reproduced. With increasing
values of the quenched disorder the values of ΔHmin are
found to increase. A numerical relation that correlates the
temperature range in which GP exists and the cation size disorder
is obtained and found to be in agreement with some reported
data.
