de Haas–van Alphen spectra of the shape-memory alloy AuZn

Abstract The martensitic transition (MT) is found in a wide range of biological, chemical and condensed-matter systems. In spite of technological interest in the MT, many fundamentals remain unclear. In this paper, we use de Haas–van Alphen oscillations to study the martensitic phase of AuZn. The oscillations show that there is a single-variant low-temperature phase, and that the AuZn samples are exceptionally pure; hence, the MT is an intrinsic, rather than an extrinsic effect. Taken with other data that indicate that there are no precursor phases, this suggests that AuZn is an excellent “model” MT system, and that it should be possible to describe the transformation in terms of a free-energy model requiring only simple input parameters.