Pulse-Echo Technique for Angular Dependent Magnetoacoustic Studies
Abstract
The pulse-echo ultrasonic technique is the only method to investigate the tensor of the so-called area coefficient, which describes the strain influence on the Fermi surface of a material. This technique has been used to study the layered superconductor Sr2RuO4 at temperatures down to 45 mK and in fields of up to 33 T. We scanned the orientation of the field in the bc-plane of the crystal and performed field and temperature sweeps at specific angles selected with a precision of about 1 degree. The wave vector of studied c11 mode coincided with the axis of rotation and was always perpendicular to the field direction. The observed quantum oscillations were the strongest at small angles between the field and the c direction of the crystal. The three frequencies of the quantum oscillations Fα = 3.02 kTesla, Fβ = 12.74 kTesla and Fγ = 18.44 kTesla as well as two values of the effective masses mα = 3.2mc and mβ = 5.5me associated with the α, β, and γ sheets of the Fermi surface measured at zero angle, are in good agreement with the known values. As expected for the cylindrical Fermi surfaces, the frequencies followed a 1/cosθ law. These results demonstrate that the technique has good performance.
- Publication:
-
Low Temperature Physics
- Pub Date:
- September 2006
- DOI:
- 10.1063/1.2355346
- Bibcode:
- 2006AIPC..850.1661S
- Keywords:
-
- 72.55.+s;
- 71.18.+y;
- 74.25.Ld;
- 74.70.Pq;
- Magnetoacoustic effects;
- Fermi surface: calculations and measurements;
- effective mass g factor;
- Mechanical and acoustical properties elasticity and ultrasonic attenuation;
- Ruthenates