  Present study reveals that the free energy landscape of the
La5/8-yPryCa3/8MnO3 (LPCMO) system could be modified by elastic strain
interaction in the epitaxial thin films. Epitaxial LPCMO thin films of various
thicknesses are grown on LaAlO3 substrate by pulsed laser deposition. With
increasing thickness, by virtue of island growth morphology, strain disorder is
invoked in thin films during strain relaxation process. The length-scale of
phase separation is found to be highly correlated with strain disorder.
Magneto-transport measurements demonstrate that coherent strain stabilizes
charge ordered insulating phase while strain disorder stabilizes metallic
phase. Resistivity under cooling and heating in unequal field (CHUF) protocol
exhibits lower value of freezing temperature for strain disordered films
compared to bulk system. Raman spectroscopy reveals that the charge ordered
insulating and ferromagnetic metallic phases are structurally dissimilar and
possess monoclinic and rhombohedral like symmetries respectively. Interfaces
between two phases strongly influence low temperature glassy metastable state
resulting in different phase separation states in the LPCMO thin films.
