Acoustic phonon dispersion in single-crystal

Haluška, M.; Havlik, Denis; Kirlinger, G.; Schranz, W.

doi:10.1088/0953-8984/11/4/008

Cited by 6 publications

(3 citation statements)

References 19 publications

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“…Another example concerns the order-disorder phase transition in C 60 single crystals. We have measured the elastic response in the vicinity of the phase transition by Dynamic Mechanical Analysis and Continuous Wave resonance technique (Haluska et al, 1999). In these crystals the elastic anomaly seems to be fully suppressed in the adiabatic limit due to the large thermal expansivity at the phase transition (Dolinar and Schranz, 1997).…”

Section: Isothermal-adiabatic Crossovermentioning

confidence: 99%

Low amplitude, low frequency elastic measurements using Dynamic Mechanical Analyzer (DMA) spectroscopy

Salje¹,

Schranz

2010

Zeitschrift Für Kristallographie

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The applications of DMA methods for the investigation of the dynamical mechanical properties of materials are reviewed. Experimental details of this method are described including the combination of DMA with X-ray rocking curve measurements to investigate the details of the domain patterns. Emphasis is given to the effect of phase transitions, in particular in ferroelastic and co-elastic systems where the ‘easy’ movement of domain boundaries, twin walls and other interfaces lead to super-elastic softening of the material. Thermodynamic constraints, such as in the adiabatic-isothermal crossover are discussed. Smooth, ballistic propagation of domain walls are contrasted with the jerky behaviour of interfaces when phase transitions of first order are investigated. It is shown that for the ballistic behaviour, momentum driven wall movements are common and that their representation in Cole-Cole plots leads to depressed semi-circles, similar to methods used in dielectric spectroscopy. In jerky elastic responses the energy dissipation follows power law dependences. Domain wall pinning and domain wall freezing is discussed in some detail.

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Section: Isothermal-adiabatic Crossovermentioning

confidence: 99%

Low amplitude, low frequency elastic measurements using Dynamic Mechanical Analyzer (DMA) spectroscopy

Salje¹,

Schranz

2010

Zeitschrift Für Kristallographie

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“…The analysis of the results of elastic properties' investigation by the low-frequency methods, for example DMA, requires taking into regard the effect of thermal relaxation, which strongly depends on the geometric size of the sample [51][52][53]. As the relative changes in the elastic properties of the RLHS crystal are analysed, it is assumed that the relative change in the storage modulus DE is proportional to the relative change in the elasticity tensor c 0 eff .…”

Section: Wiesnermentioning

confidence: 99%

Ferroelastic crystals and their nonlinear elastic properties observed in frequency range from gigahertz to milihertz

Wiesner

2009

Phase Transitions

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The experiments reported in this article have been performed to unify the results of earlier and recent determinations of parameters describing the elastic properties of Rb 4 LiH 3 (SO 4 ) 4 , LiCsSO 4 (LCS) and KH 2 PO 4 crystals measured by different experimental methods. The above crystals undergo a second-order phase transition, incommensurate phase transition (PT) and a first-order but close to second-order phase transition, respectively. To investigate the elastic properties of the crystals in the frequency range from 10 À1 to 10 10 Hz, five experimental methods were applied: dynamic mechanical analysis, piezoelectric resonance, composite oscillator bar, ultrasonic wave propagation and Brillouin light scattering. The results of the experiments allowed identification of the processes contributing to the elastic response of the crystals investigated. Moreover, for the LCS crystal a model of the incommensurate PT was presented.

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“…This is a solid characterized by equal angles and all faces in the regular polygon. Since the discovery of the method for producing bulk quantities of C 60 , fullerene science has spread out rapidly in to solid-state physics, molecular physics, chemical sciences and material sciences [4].…”

Section: Introductionmentioning

confidence: 99%

Low Temperature Thermal Expansion of Cubic Fullerene C60

2016

IJSR

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Abstract:The anisotropy in the low temperature thermal expansion of C 60 is analyzed theoretically. The generalized Grüneisen parameters (Gps) of the elastic waves propagating in different directions in C 60 are calculated using the second-order elastic constants and the first-order pressure derivatives of the second-order elastic constants. The expressions of effective second-order elastic constants are used to evaluate the six third-order elastic constants of the C 60 system. The third-order elastic constants of C 60 thus obtained are negative. The values of generalized Grüneisen parameters are positive. The Brugger gamma is calculated and the low-temperature limit of Grüneisen gamma is determined using the procedure of Menon and Ramji Rao. The value of low-temperature limit of Grüneisen gamma is positive. Therefore we expect volume expansion to be positive to absolute zero for C 60 system. The anisotropy of thermal expansion along the three axis of crystal is less. PACS number (s): 62.20 D, 74.25 L, 74.62

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Acoustic phonon dispersion in single-crystal

Cited by 6 publications

References 19 publications

Low amplitude, low frequency elastic measurements using Dynamic Mechanical Analyzer (DMA) spectroscopy

Low amplitude, low frequency elastic measurements using Dynamic Mechanical Analyzer (DMA) spectroscopy

Ferroelastic crystals and their nonlinear elastic properties observed in frequency range from gigahertz to milihertz

Low Temperature Thermal Expansion of Cubic Fullerene C60

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