Abstract: Poly (Ethelyne) Oxide/Zirconium dioxide (PEO+xZrO2 ) (x = 0, 5, 10, 25 and 50% wt.) membranes were obtained using 2.5% wt. acetonitrile solution. Room temperature X-Ray diffraction (XRD) showed the presence of a mixture of phases for the whole range of ZrO2 content. Raman measurements (Raman Spectroscopy (RS)) at room temperature revealed the presence of a mixture of vibrational states for the two phases PEO and ZrO2 , respectively. The two techniques XRD and SR confirmed an exponential trend of the increase in the relative volume of ZrO2 on the basis of the content of ZrO2 . The thermal stability of the (PEO+xZrO2 ) membranes was corroborated using DSC measurements. The presence of ZrO2 in the host matrix promoted the reduction of the energy needed to obtain the fusion of the complex polymer and with it an implicit increase of the disorder, coinciding with the two XRD and RS measurements.