Rapid Microwave Synthesis and Structural Phase Diagram of Doped Yttrium Manganate
Last year Fred Marlton did his Honours in Chemistry at ANU, and this year the little paper we wrote came out. It was more done to give Fred a sense of the publishing process, and communicating science in that way, but it does have a few handy results in it as well, ones that could save time and effort for people synthesising compounds from the family LnxY1−xMnO3. The paper is published in Zeitschrift für Naturforschung B, which is a venerable journal with, based on this experience, an excellent editorial process. The abstract can be viewed here.
In essence the title says it all; we used microwave sintering to make the samples, which saved an order of magnitude in time and electricity, and allowed Fred to quickly map out the whole phase diagram describing where these compounds form.
What we found was that solid-state microwave synthesis allows manufacture of high-quality samples in hours rather than days. The resulting phase diagram accords well with results from the literature, and from calculations based on the Goldschmidt tolerance factor for the stability of perovskite structures, suggesting that the transformation from hexagonal to perovskite with doping is driven essentially by ion sizes. Some results concerning the microwave synthesis of BaLnInO4 compounds, where Ln is a lanthanide, are noted. Microwave sintering of BaNdInO4 yields single-phase samples where conventional sintering does not.