Synthesis and characterization of methylammonium phosphates as crystalline approximants for anhydrous, low melting phosphate glasses.

Low-melting methylammonium phosphate glasses are synthesized from crystalline starting agents. To this end crystalline tris(methylammonium) cyclotriphosphate [CHNH]PO, was synthesized by a novel and simple synthesis route from PO and -methylformamide. It, undergoes an irreversible phase transition to methylammonium -polyphosphate [CHNH]PO.

Deep inside the ceramic texture: A microscopic-chemical approach to the phase transition via partial-sintering processes in ancient ceramic matrices.

High-resolution microscopy investigations on ancient ceramics recommend the complex progression of crystalline phases in an antique object via the sintering process. Based on materials-science point of view, sintering is not a routinely reaction in all crystalline phases with the same crystallographic pattern, but also is a transition pathway. Sintering depends on the processing of raw materials via the manufacturing process.