UNUSUAL BEHAVIOR OF THERMAL-CONDUCTIVITY OF A CRYSTALLINE-NACL-OPAL NANOCOMPOSITE

An opal-based nanocomposite has been prepared with NaCl incorporated i n its pores. The nanocomposite was produced by impregnating the opal w ith a NaCl solution at room temperature. Thermal conductivity of the n anocomposite has been measured in the temperature range 4.2-300 K. The effective heat conductivity of the nanocomposite was found to be equa l to that of pure opal. The observed phenomenon can be explained by as suming that NaCl resides in opal pores in the form of noncontacting ne edles, thus precluding heat propagation through it. (C) 1998 American Institute of Physics.