Solid-state physics with ultrasound – new PPMS options
We are happy to introduce the brand-new USEC option (ultrasonic elastic constant) for our Physical Property Measurement System PPMS. With this option there is now for the first time a commercial solution for measurements of elastic properties by ultrasound available.
The measurement principle is rather simple: An ultrasonic pulse is created on the sample surface by a piezoelectric transducer. This pulse travels through the sample and can either be detected on the opposite side or its reflection is measured.
The USEC option detects even the slightest changes in velocity and is perfectly suited for tracking phase transitions.
It ideally complements well-established PPMS measurement options like magnetometry, heat capacity and more. Professor Yoshizawa of the Iwate University in Morioka Japan presented the USCE option during this year’s SCES conference in Prague (see fig.1).
Fig. 1: Prof Yoshizawa (on the right) explains measurement details
The sample material was UAu2Si2 – a substance only rarely analyzed so far. Just recently, this compound has been synthesized in single crystalline form. In contrast to earlier publications, it was shown that UAu2Si2 has antiferromagnetic properties below 19 K [1]. Earlier measurements found the substance to be ferromagnetic which probably corresponds to polycrystalline properties of the used sample.
Fig. 2: Temperature-dependency of the longitudinal mode in UAu2Si2
Fig. 2 shows the frequency as a function of temperature (measuring points in 0.5 K increments). The longitudinal mode is applied along the crystallographic direction 100 at zero field. The magnetic transition clearly shows at about 20 K.
The measurement was performed at the “Materials Growth and Measurement Laboratory” in Prague: http://mgml.eu
[1] Chihiro Tabata et al. „Peculiar magnetism of UAu2Si2“, Physical Review B 94, 214414 (2016).
