On the application of new equations to derive acoustic, thermodynamic and other properties of iron phosphate semiconducting glass

We made an exhaustive study of semiconducting (Fe2O3)(0.38)(P2O5)(0.62) gla ss and derived several important properties. They are in satisfactory agree ment with experiment for those found in literature, and the other values ob tained by different methods are found to be interconsistent, Using Thurston 's equations and the pressure derivative of beta and delta, Bhatia-Singh's parameters, we;have calculated and compared the pressure derivatives of sec ond order elastic constants. Gruneisen gammas (gamma(g)(L), gamma(g)(T), ga mma(g)(el), gamma(g)(th)) are calculated using various methods. Pressure de rivative of bulk modulus (C-1) was evaluated assuming hard sphere model, an d effective packing fraction (eta(eff)) was obtained from the compressibili ty equation of state. C-1' [=(dC(1)/dP)(T)] = 2(gamma(g)(th)) was calculate d using the compressibility equation of state, and from beta and delta. (ga mma(g)(th)) and (gamma(g)(th))' [= d gamma(g)(th)/dP] is important in super conducting studies, and in the evaluation of the second Gruneisen constant. Using Einstein and Debye's equation, molar heat capacity was evaluated. Se cond Gruneisen constant Q [= (partial derivative ln gamma(g)/partial deriva tive ln V)(T)] and Anderson-Gruneisen parameter delta(AG) [= -1/alpha K-T(p artial derivative K-T/partial derivative T)(P)] was also evaluated. Smith-N ath-DeLaunay's (SND) equation was used to obtain absorption band position. Phonon frequencies were calculated using Bhatia-Singh's equations for the e valuation of C-11 and C-44. We made a self consistent check in the calculat ion of C-11 and C-44 from the slopes of omega(L)(k) and omega(T)(k) at low k values. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.