Low-frequency superelasticity and nonlinear elastic behavior of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">SrTiO</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>crystals

Kityk, A. V.; Schranz, W.; Sondergeld, Peter; Havlik, Denis; Salje, Ekhard K. H.; Scott, J. F.

doi:10.1103/physrevb.61.946

Cited by 156 publications

(127 citation statements)

References 21 publications

Supporting

Mentioning

119

Contrasting

Order By: Relevance

“…In this case, internal interfaces such as twin boundaries move with little restoring forces through samples when external stresses are applied (Lee et al 2006). The effective elastic bulk and shear moduli are then completely dominated by such moving interfaces and reductions, in stiffness by one order of magnitude, are common (Kityk et al 2000;Harrison et al 2004). The elastic moduli cease to be materials parameters and largely depend on the mobility of interfaces, boundary conditions and the internal structures of interfaces.…”

Section: Introductionmentioning

confidence: 99%

(An)elastic softening from static grain boundaries and possible effects on seismic wave propagation

Salje

2008

Phys Chem Minerals

View full text Add to dashboard Cite

It is argued that low-frequency wave propagation shows, in most cases, very little dependence on the atomistic properties of grain boundaries if the thickness of the grain boundary is atomistically thin while the grain size is in the mm region. Large effects do exist for specific textures (e.g. the brick wall texture). The essential ingredient for the assessment of an-elastic and non-linear elastic features of seismic wave propagation does not primarily depend on the structural properties of immobile, dry grain boundaries but on the way the grain boundary properties can be related to those of macroscopic mineral assemblies. Specific results for coated sphere textures are derived using Hashin-Shtrikman theory. An-elastic seismic features are more likely to be related to the mobility of boundaries and dislocations which can be attached to the grain boundaries, or bulk-related defect structures, rather than the intrinsic materials properties of the grain boundaries.

show abstract

Section: Introductionmentioning

confidence: 99%

(An)elastic softening from static grain boundaries and possible effects on seismic wave propagation

Salje

2008

Phys Chem Minerals

View full text Add to dashboard Cite

show abstract

“…This indicates that the elastic hardening and increase of the elastic damping (as expressed by Q −1 ) during cooling relates to gradual domain wall freezing with an extremely broad excitation spectrum. Such thermal behavior is commonly observed in ferroelastic materials [38,39].…”

Section: Discussionmentioning

confidence: 96%

Avalanche criticalities and elastic and calorimetric anomalies of the transition from cubic Cu-Al-Ni to a mixture of18Rand2Hstructures

et al. 2016

View full text Add to dashboard Cite

We studied the two-step martensitic transition of a Cu-Al-Ni shape-memory alloy by calorimetry, acoustic emission (AE), and resonant ultrasound spectroscopy (RUS) measurements. The transition occurs under cooling from the cubic (β, F m3m) parent phase near 242 K to a mixture of orthorhombic 2H and monoclinic 18R phases. Heating leads first to the back transformation of small 18R domains to β and/or 2H near 255 K, and then to the transformation 2H to β near 280 K. The total transformation enthalpy is H T = 328 ± 10 J/mol and is observed as one large latent heat peak under cooling. The back-transformation entropy under heating breaks down into a large component 18R to β at 255 K and a smaller, smeared component of the transformation 2H to β near 280 K. The proportions inside the phase mixture depend on the thermal history of the sample. The elastic response of the sample is dominated by large elastic softening during cooling. The weakening of the elastic shear modulus shows a peak at 242 K, which is typical for the formation of complex microstructures. Cooling the sample further leads to additional changes of the microstructure and domain wall freezing, which is seen by gradual elastic hardening and increasing damping of the RUS signal. Heating from 220 K to room temperature leads to elastic anomalies due to the initial transformation, which is now shifted to high temperatures. The transition is smeared over a wider temperature interval and shows strong elastic damping. The shear modulus of the cubic phase is recovered at 280 K. The phase transformation leads to avalanches, which were recorded by AE and by time-resolved calorimetry. The cooling transition shows very extended avalanche signals in calorimetry with power-law distributions. Cooling and heating runs show AE signals over a large temperature interval above 260 K. Splitting the transformation into two martensite phases leads to power-law exponents ε ∼ 2 (β ↔ 18R) and ε ∼ 1.5 (β ↔ 2H ) while the phase mixture shows an effective AE exponent of 1.7.

show abstract

“…The spontaneous strain orientation for one twin is different from that of an adjacent twin, so movement of the wall separating them can change the total macroscopic strain of the crystal. If the twin wall moves in response to an applied shear stress, the total resulting strain can become substantially greater than would occur by simple lattice bending and the crystal will be anomalously soft (Schranz et al, 1999;Kityk et al, 2000aKityk et al, , 2000bBinder and Knorr, 2001;Lemanov et al, 2002;Harrison and Redfern, 2002;Harrison et al, 2003Harrison et al, , 2004aHarrison et al, , 2004bHarrison et al, , 2004c. This mechanism of softening involves some dissipation of energy and is anelastic in character.…”

Section: Anelasticity and The Influence Of Transformation Twin Wallsmentioning

confidence: 99%

“…It was recognised from the early days of elastic constant measurements on SrTiO 3 that the displacement of transformation twin walls in response to an applied shear stress can give rise to additional softening and attenuation effects (Rehwald, 1971;Fossheim and Berre, 1972). These can be large in magnitude, giving rise to so called superelasticity (Schranz et al, 1999;Kityk et al, 2000aKityk et al, , 2000bBinder and Knorr, 2001;Lemanov et al, 2002;Harrison and Redfern, 2002;Harrison et al, 2003Harrison et al, , 2004aHarrison et al, , 2004bHarrison et al, , 2004c. Equivalent behaviour in silicate perovskites cannot be investigated directly because of the high confining pressure required to stabilise them, but a useful analogue system is the binary solid solution CaTiO 3 SrTiO 3 (CST).…”

Section: Figurementioning

confidence: 99%

“…Expressions for the individual elastic constants are given formally by applying (7) to Equation 1 (Slonczewski and Thomas, 1970). This has been widely used in relation to Landau expansions out to fourth order in q (second order transitions), but only recently extended to the full sixth order potential given above (see, also, Kityk et al, 2000a). For the Pm3 m ↔ I4/mcm transition, individual elastic constants, such as C 11 and C 44 , are expected to follow (8) (9) where (10) (11) Bulk (K) and shear (G) moduli can be calculated from the individual elastic constants in the usual way by taking the average of Voigt and Reuss limits (Hill, 1952) or by using Hashin Shtrikman bounds (Watt, 1979;Watt and Peselnik, 1980).…”

Section: Elastic Anomalies As a Function Of Temperaturementioning

confidence: 99%

See 1 more Smart Citation

Structural evolution, strain and elasticity of perovskites at high pressures and temperatures

Carpenter

Sondergeld

et al. 2006

Journal of Mineralogical and Petrological Sciences

View full text Add to dashboard Cite

Octahedral tilting transitions in perovskites are usually identified by the significant lattice distortions which accompany them. The underlying mechanism of coupling between the tilts and the macroscopic strain also gives rise to large anomalies in single crystal and bulk elastic moduli. Landau theory provides an effective framework for describing these different changes in properties and relating them, quantitatively, to the evolution of the driving order parameter for the transition. This approach has been used to analyse the overall elastic behaviour of perovskites belonging to the CaTiO 3 SrTiO 3 (CST) solid solution, which is expected to be closely analogous to the behaviour of silicate perovskites at higher pressures and temperatures. Pm3 m ↔ I4/mcm and I4/mcm ↔ Pnma transitions in CST perovskites are marked by changes in the shear modulus of ~ 10 30%. The evolution of the order parameter and, hence, of the octahedral tilt angles through these can be followed through the variations of spontaneous strains extracted from high resolution lattice parameter data. Contributions to the elastic softening which are due to strain/octahedral tilt coupling have been calculated using a fully parameterised Landau model of the Pm3 m ↔ I4/mcm transition as a function of temperature, pressure and composition. Differences between calculated elastic constants and experimental data from Dynamical Mechanical Analysis, pulse echo ultrasonics and Resonant Ultrasound Spectroscopy suggest that a proportion of the total softening in tetragonal samples may be due to anelastic effects. The anelastic contributions are observed at frequencies of both a few Hz and 10's of MHz, and can be understood in terms of strain contributions arising from movements of transformation twin walls in response to an externally applied shear stress. Similar transitions in other perovskites are likely to display small anomalies in the bulk modulus, due to weak coupling between octahedral tilts and volume strain, but much larger anomalies in the shear modulus. The elastic properties of tetragonal and orthorhombic structures are likely to be quite different due to different anelastic contributions from twin wall displacements.

show abstract

Low-frequency superelasticity and nonlinear elastic behavior ofSrTiO3crystals

Cited by 156 publications

References 21 publications

(An)elastic softening from static grain boundaries and possible effects on seismic wave propagation

(An)elastic softening from static grain boundaries and possible effects on seismic wave propagation

Avalanche criticalities and elastic and calorimetric anomalies of the transition from cubic Cu-Al-Ni to a mixture of18Rand2Hstructures

Structural evolution, strain and elasticity of perovskites at high pressures and temperatures

Contact Info

Product

Resources

About