When a burst of an rf signal is applied to the transmitter, the latter generates an ultrasound pulse with the same duration. This ultrasound pulse propagates across the sample and, when it arrives at the receiver transducer, generates an rf pulse. The ultrasound pulse propagates back and forth and creates additional rf pulses at the receiver—a so called “echo train.” The sound propagation time is determined by the sound velocity and hence by the associated elastic constant. The time evolution of the amplitude of the received pulse is defined by the sound attenuation. Both the ultrasound velocity and attenuation are intrinsic properties of the material and can be changed only by varying some external parameters such as temperature, magnetic field or pressure, for example. Investigation of a relative change of the velocity and attenuation on these external parameters is implemented at the MagLab.
Images & Sample Data
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Sr2RuO4 sample mounted on a sample holder used in pulse-echo technique.
Sr2RuO4 sample mounted on a sample holder used in pulse-echo technique.
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Quantum oscillations of ultrasound velocity observed by the pulse-echo technique in Sr2RuO4.
Quantum oscillations of ultrasound velocity observed by the pulse-echo technique in Sr2RuO4.
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Magnetic field dependence of the ultrasound c11-mode velocity in URu2Si2 at 137 MHz and different temperatures
Magnetic field dependence of the ultrasound c11-mode velocity in URu2Si2 at 137 MHz and different temperatures
https://nationalmaglab.org/user-facilities/dc-field/dcfield-techniques/pulse-echo-ultrasound-dc?tmpl=component&print=1#sigProIdf99dd4e9fe
Details
Resistive Magnets
- 25 Tesla, cell 5
- 30 Tesla, cell 2
- 31 Tesla, cell 7
- 31 Tesla, cell 9
- 35 Tesla, cell 8
- 35 Tesla, cell 12
- 36 Tesla, cell 14
- 45 Tesla, cell 15
Superconducting Magnets
- Signal Generator Agilent E4424B
- Signal Generator Agilent E8257D
- Signal Generator Agilent N5171B
- Signal Generator Stanford Research Systems SG382
- Function generator Stanford Research Systems DS345
- Digital Delay / Pulse generator DG535
- Gated Integrator & Boxcar Averager SR250
- Preamplifier SR240
- Colby Instrument Programmable Delay Line PDL-100A-100n
- Oscilloscope Tektronix TDG3034B
- Oscilloscope LeCroy HDO4054
- Homemade two channel (Amplitude & Phase) RF detector (30 – 2700 MHz)
Relevant Publications
Nomura, T., et al., Enhanced spin correlations in the Bose-Einstein condensate compound Sr3Cr2O8, Physical Review B , 102, 165144 (2020) Read online
Grossmann, J., et al., Highly sensitive simple homodyne phase detector for ultrasonic pulse-echo measurements, Review of Scientific Instruments, 87, 4, 044901 (2016) Read online
O. Svitelskiy, et al., Influence of hydrostatic pressure on the magnetic phase diagram of superconducting Sr2RuO4 by ultrasonic attenuation, Phys. Rev. B (2008) Read online
O. Svitelskiy, et al., Elastic properties of Gd5(Si2Ge2) studied by ultrasonic pulse-echo technique, Phys. Rev. B 74 (2006) Read online
A. Suslov, et al., Ultrasonic instrumentation for measurements in high magnetic fields. Part I: continuous magnetic fields, Review of Scientific Instruments 77 (2006) Read online