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

Abstract

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.

Strain rate dependence of twinning avalanches at high speed impact

“…A similar crossover at much lower strain rates was previously reported experimentally. 16 We show, in this Letter, that the crossover point coincides with the onset of the collapse of the absorbed energy at the yield point.…”

Electronic nematic susceptibility of iron-based superconductors

“…In addition to the static three-point bending measurements in the capacitance dilatometer, ultralowfrequency dynamic three-point bending measurements of BaFe 2 As 2 were performed using a Diamond DMA (dynamical mechanical analyzer) from PerkinElmer [109]. Here, samples are subjected to a force F = F S + F D exp(iωt) with a dynamic component at the very low frequency of 1 Hz.…”

Mechanical spectroscopy in twinned minerals: Simulation of resonance patterns at high frequencies

“…Mechanical properties of minerals have been analyzed for many decades with emphasis on single crystals (e.g., Haussuehl 1960). With the advent of (multi) ferroic materials in physics and material sciences, the same techniques, such as low-frequency DMA measurements and high-frequency resonant ultrasonic spectroscopy (RUS) have been used to characterize mechanical properties and yield significant advances in both experimental techniques and the interpretation of mechanical spectra (Salje and Schranz 2011;Carpenter and Salje 1998;Scott et al 2012). Recent work in the mineralogical literature such as Zhang et al (2012aZhang et al ( , 2012b, Prencipe et al (2009), Harrison et al (2003Harrison et al ( , 2004aHarrison et al ( , 2004b, Ohno et al (2000), Isaak and Ohno (2003), Isaak et al (2006), McKnight et al (2007), Carpenter et al (2007, and Salje et al (2011aSalje et al ( , 2011bSalje et al ( , 2011c use DMA and RUS methods to determine the temperature and pressure dependence of elastic moduli to understand by which mechanisms phase transitions in minerals occur.…”

“…Physically, this model corresponds to a Debye-like relaxation process with a distribution of relaxation times around t o . The shape of the distribution and its width are described by the exponent m [0 < m ≤ 1, see Salje and Schranz (2011), for a review].…”