Figure 1

Top: de Haas–van Alphen oscillations observed in the magnetic susceptibility of AuZn at 10 K (upper), 55 K (middle), and 68 K (lower). The magnetic field is applied parallel to the [110] direction of the austenite phase; curves are offset for clarity. Bottom: the measured signal ($\propto dM/dB\times dB/dt$) at 100 K. The positions of the marked dHvA oscillations are also shown as index versus $1/B$ (points); the straight line fitted to these points has a gradient of $4590\pm 80\mathrm{T}$, showing that the oscillations are due to the austenite Fermi surface.Reuse & Permissions

Figure 2

(a) Fourier-transform spectra of the de Haas–van Alphen oscillations at 600 mK. (b) Detail of the peak at 1140 T at two temperatures straddling the phase transition at $T=66.5\mathrm{K}$. (c) Detail of the peak at 4660 T at the same two temperatures. (d) The amplitudes of the 4660 T peak (data points) as a function of temperature. The sharp drop in the amplitude occurs at the phase transition. The dotted lines represent fits to the Lifshitz-Kosevich formula described in the text. All the data are taken with the field applied parallel to the austenite [110] direction.Reuse & Permissions

Figure 3

Fermi surface sections of AuZn from the band-structure calculations, together with the quasiparticle orbits (bold lines) that best correspond to the four measured de Haas–van Alphen oscillations. (a), (b), (c), and (d) occur in the order in which the frequencies appear in Table . There are four martensite variants corresponding to the four body diagonals of the cubic austenite phase [4]. Thus when the field is applied along the [110] direction of the austenite, geometry dictates that the field lies along two inequivalent directions in the martensite Brillouin zone. One direction leads to orbits whose plane is perpendicular to the hexagonal plane of the Brillouin zone, as is the case in (a), while the other produces orbits whose plane is inclined at around 60° to the hexagonal plane, as is the case in (b) and (c). (d) shows the austenite Fermi surface and orbit.Reuse & Permissions

Figure 4

Dingle analysis of the amplitudes of the 1141 T frequency of martensite dHvA oscillation at three temperatures. It is suggested that $B_{\mathrm{c}}$ corresponds to the field at which the cyclotron radius ($\approx 50\mathrm{nm}$) is representative of the size of a single martensite variant within the bulk of the sample.Reuse & Permissions