Defect-induced heterogeneous transformations and thermal growth in athermal martensite

Exploring the solid state phase transition in dl-norvaline with terahertz spectroscopy

Experimental and theoretical demonstration of the power of terahertz spectroscopy to provide novel insights into solid-state phase-transformations in organic materials.

Hysteresis and magnetization jumps in the T=0 dynamics of spin glasses

We present results from Monte Carlo simulations of hysteresis in the zero-temperature ( T=0 ) dynamics of the Sherrington-Kirkpatrick spin glass model. We study the statistics of magnetization-jumps (denoted as Deltam ) in response to a time-dependent magnetic field H (t) , which increases or decreases with constant increments Delta as H(t)-->H(t)+/-Delta . In particular, we focus on the field dependence of the Deltam -distribution function P(Deltam,H) . We formulate arguments to understand the variation of P ( Deltam,H ) along the hysteresis loop in the weak-disorder limit.

Acoustic emission and shape memory effect in the martensitic transformation

Acoustic emission signals are known to exhibit a high degree of reproducibility in time and show correlations with the growth and shrinkage of martensite domains when athermal martensites are subjected to repeated thermal cycling in a restricted temperature range. We show that a recently introduced two dimensional model for the martensitic transformation mimics these features. We also show that these features are related to the shape memory effect where near full reversal of morphological features are seen under these thermal cycling conditions.