Transition to glassy solutions in the Y(HCOO)3–Ba(HCOO)2–Cu(HCOO)2–H2O quaternary system proceeding from microwave dielectric data

Abstract

Microwave dielectric properties and electrical conductivity were studied in aqueous solutions along the section of the Y(HCOO)₃–Ba(НСОО)₂–Cu(HCOO)₂–H₂O quaternary system where the total salt concentration is from 0.3 to 18.9 mol % (the salt component ratio is 1: 2: 3). Thereby, unsaturated, saturated, and supersaturated solutions were included into the description. The measurements were performed at 298 K at frequencies of 13, 16, 19, and 25 GHz. Static dielectric permittivities (dielectric constants) and dielectric relaxation times, the key parameters of state of water molecules, were calculated. At the concentrations where the initial water structure is nonexistent and the dielectric constants of solutions have low values, water molecules have slowed dynamics and complex ion–water species are formed. The appearance of these species determines the formation of metastable solutions and glassy phases. This makes it possible to manufacture homogeneous multicomponent water–salt compositions in solid state to be used as precursors for the production of oxide materials.