Abstract
The infrared absorption in widnow materials such as NaCI, KBr, and Kul, which are commercially availanle in Japan, has been studied by means of thecalorimetric technique with a step-tunable CW CO2 maser. The absorptlon coeficientat10.6μm of NaCl is measured to be 2.5×10-3 cm-1, which is almost twice of theintrinsic multiphonnn absorption. KCI material has the10.6μ m absorption coefficientof 6×10-4 cm-1, which is about one ordex higher than the intrinsic multiphononabsorption coefficient of 7×10-5 cm-1. For KBr, the absorption coefficient at 10.6μ mis 1×10-3 cm-1, which is about four order higher than the intrinsic multiphononabsorption of 2×10-7 cm-1. (One absorption band at 9.29 μm is observed ln KBr) Three different techniques are tried to separate out bulk and surface absorption.This calorimetric technique is used to obtain the dependence of absorption coefficienton the sample's position in an NaCI ingot.
