Effect of processing Conditions on <TEX>$3,400cm^{-1}$</TEX> -OH Peak in IR Transmitting Heavy Metal Fluoride Glasses

,; ,; ,; ,

J. Korean Ceram. Soc. > Volume 21(3); 1984 > Article

Journal of the Korean Ceramic Society 1984;21(3): 231.

적외선 투과성 플루오르화 중금속 유리의 $3,400cm^{-1}$ -OH 흡수에 미치는 가공조건의 영향

장기호, C. T Moynihan

육군사관학교 화학과

Effect of processing Conditions on $3,400cm^{-1}$ -OH Peak in IR Transmitting Heavy Metal Fluoride Glasses

ABSTRACT

Heavy metal fluoride glasses exhibit considerable promise as high transparency materials from the UV to the IR. These glasses are prepared by fusion of the mixture of metal fulorides($ZrF_4$, $BaF_2$, $LaF_3$ etc) at 800-1, 00$0^{circ}C$ under the inert$(N_2)$ or reactive ($CCl_4$, $Cl_2$) atmosphere following the casting into glass on cooling. Infrared absorption at the 3, 400 cm-1 -OH peak has been measured as a function of thickness for several ZrF-$BaF_2$-LaF and $HfF_4$-$BaF_2$-$LaF_3$ glasses to separate contributions from bulk and surface -OH. For glasses melted under $CCl_4$ reactive atmosphere the peak is due almost entirely to surface-OH. and melting in a closed reactor was best for removing -OH. In ambient atmosphere the -OH peak exhibited no time dependence over a 30 d period indicating a very small rate of surface attack by atmospheric H2O. Removal of -OH absorption processing was generally easier and more complete for the $BaF_2$/ThF4-glasses than for the $ZrF_4$-or $HfF_4$-based glasses.