EXAFS STUDY FOR ANHARMONICITY OF CUBR

New formalism of EXAFS analysis for anharmonic system has been applied to anharmonic system of CuBr at temperatures, 150, 300, and 400 K. Th e new formalism gives the consistent results on the second cumulants w ith a previous work, and the additional constants such as the local th ermal expansion coefficient, alpha(L), force constant, k(0), and anhar monic parameter, beta has been derived. The obtained values were alpha (L) = (6.19 +/- 0.05) x 10(-5)/K, k(0) = (41 +/- 5) N/m, and beta = (6 .0 +/- 0.5) x 10(11) N/m(2), respectively, for Br-Cu bond. The higher cumulants were derived in terms of anharmonic parameter, force constan t and temperature.