Precision ultrasonic velocity measurements for the study of the low temperature acoustic properties in defective materials

Vanelstraete, A; Laermans, C.

doi:10.1016/0921-5093(89)90775-2

Cited by 9 publications

(5 citation statements)

References 11 publications

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“…The attenuation was measured using a standard pulse-echo technique, while accurate measurements of the velocity change were done using a pulse interference method, developed in our laboratory. 15 For converting the electromagnetic signal into a longitudinal elastic wave, a LiNbO 3 transducer was used. Figure 1 shows the attenuation as a function of temperature for our a-GeO 2 sample, measured at two frequencies: 80 and 210 MHz.…”

Section: Experimental Procedures and Sample Propertiesmentioning

confidence: 99%

Tunneling states in vitreousGeO2s

Laermans¹,

Keppens²,

Weeks³

1997

Phys. Rev. B

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Ultrasonic measurements of the attenuation and the velocity variation have been carried out in amorphous GeO 2 at low temperature ͑0.3-10 K͒ and high frequencies ͑80-210 MHz͒. From numerical fits to the tunneling model, the typical parameters of the tunneling states ͑TS͒ were determined and compared to those found for vitreous SiO 2 . The study reveals that in a-GeO 2 , which is considered as a close structural analog to a-SiO 2 , although the density of states is found to be very similar in both materials, the coupling between the TS and the phonons is significantly smaller. In the model of coupled tetrahedra as the origin of the TS, this difference can be understood in view of the fact that numerical calculations about the vibrational characteristics of network amorphous solids indicate that the tetrahedra are more decoupled in vitreous GeO 2 than in vitreous silica.

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Section: Experimental Procedures and Sample Propertiesmentioning

confidence: 99%

Tunneling states in vitreousGeO2s

Laermans¹,

Keppens²,

Weeks³

1997

Phys. Rev. B

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“…The same result is obtained for the LER geometry. For X cut crystalline quartz no change in v s within a precision of 0.1 ppm was observed below 10 K [ 23 – 25 ]. The measured values of below 10 K are in the order of 0.01 ppm/K [ 21 ].…”

Section: Resultsmentioning

confidence: 99%

“…This is much higher than expected from the change in v s or , as discussed above. From neutron irradiation it is known, that the change of v s with T depends strongly on the quality of the crystal, the rate of change increases linearly with the defect density [ 24 – 25 28 ]. Because the quartz resonators studied in this work are not from the same wafer and manufacturer, one might argue that the differences in ∂ ε/ ∂T can be caused by different crystal quality and material processing.…”

Section: Resultsmentioning

confidence: 99%

Impact of thermal frequency drift on highest precision force microscopy using quartz-based force sensors at low temperatures

Pielmeier¹,

Meuer²,

Schmid³

et al. 2014

Beilstein J. Nanotechnol.

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SummaryIn frequency modulation atomic force microscopy (FM-AFM) the stability of the eigenfrequency of the force sensor is of key importance for highest precision force measurements. Here, we study the influence of temperature changes on the resonance frequency of force sensors made of quartz, in a temperature range from 4.8–48 K. The sensors are based on the qPlus and length extensional principle. The frequency variation with temperature T for all sensors is negative up to 30 K and on the order of 1 ppm/K, up to 13 K, where a distinct kink appears, it is linear. Furthermore, we characterize a new type of miniaturized qPlus sensor and confirm the theoretically predicted reduction in detector noise.

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“…The variation of the ultrasound velocity was measured in three α-quartz samples with different irradiation doses in temperature range 5 -35 K. The measurements were carried out at three frequencies (270, 400 and 650 MHz) using the pulse-interference method [16], which can measure the relative change of sound velocity of 2 × 10 −7 . Figure 1 shows the temperature dependence of the sound velocity in our samples at frequency 400 MHz.…”

Section: Resultsmentioning

confidence: 99%

Ultrasound velocity in neutron‐irradiated quartz crystals above 5 K

Parshin¹,

Laermans

2004

phys. stat. sol. (c)

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A linear temperature dependence of the sound velocity above 5 K is a universal property for amorphous and disordered solids. However, there are several theoretical models, which propose the explaination of this universal behaviour at intermediate temperatures. Previous low-temperature measurements have shown that the neutron-irradiated quartz can be used for the study of the glassy dynamics. In this paper we present the results of the ultrasound velocity measurements in neutron-irradiated quartz crystals at temperatures 5 -35 K and discuss them in the framework of the different models.Introduction Thermal and acoustical properties of amorphous solids below 1 K are well described in the framework of the tunnelling model [1,2,3]. Sound velocity of amorphous solids first increases logarithmically with temperature, reaches the maximum, and than decreases also logarithmically. This temperature dependence is described by equations: (∆v/v) res,TLS = C ln(T /T 0 ) and (∆v/v) rel,TLS = −

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Precision ultrasonic velocity measurements for the study of the low temperature acoustic properties in defective materials

Cited by 9 publications

References 11 publications

Tunneling states in vitreousGeO2s

Tunneling states in vitreousGeO2s

Impact of thermal frequency drift on highest precision force microscopy using quartz-based force sensors at low temperatures

Ultrasound velocity in neutron‐irradiated quartz crystals above 5 K

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