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  • 1 Tanta University Physics Department, Faculty of Science Tanta Egypt
  • 2 Faculty of Education Physics Department Kafr El-Sheikh Egypt
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Abstract  

Films ≈350 μm of poly(vinyl-alcohol) composites, containing copper (Cu), aluminium (Al) and iron (Fe), metallic powder very fine, were prepared by a casting method. Thermal conductivity, phonon velocity, mean free path and specific heat were studied. The pure sample of PVA has a lower values of thermal conductivity than that which are doped with metals. For all samples the thermal conductivityK increases up to a certain temperatureTgg (120–160°C) and then decreases with temperature. The specific heat increase with temperature up to ≈120°C and above 120°C is nearly independent on temperature. The pure sample of PVA has small values of mean free path (L)≈0.2 Å at room temperature, but for PVA+ metalsL≈2.0 Å. The phonon velocity of pure PVA is larger than that of PVA containing metals.