Crystal Structure and Characterization of CsH5(AsO4)2: A New Cesium Pentahydrogen Arsenate, and Comparison with CsH5(PO4)2 and RbH5(AsO4)2

For developing a new aluminum brazing flux, the liquidus in the ternary system AlF3–KF–CsF was determined by DTA and visual polythermal methods. The results indicated that the region around E4 (located in AlF3 43 mol%, CsF 18 mol%, KF 39 mol%) and E5 (AlF3 45 mol%, CsF 18 mol%, KF 37 mol%), at which the melting temperatures are lower than 500°C, appears to be the best compositions for using as a modified Nocolok flux. The lower temperature region near CsAlF4 may be another candidate composition.