Distributions of avalanches in martensitic transformations

Acoustic emission across the magnetostructural transition of the giant magnetocaloricGd5Si2Ge2

“…Present results show that the temperature-driven magnetostructural transition in Gd 5 Si 2 Ge 2 proceeds by multiple steps ͑avalanches͒ joining a series of metastable states, until the system is fully transformed. This behavior has been encountered in a wide variety of driven processes in different systems ͑rever-sal of the magnetization both in standard metamagnetic transitions 31 and magnetostructural transitions, 32 martensitic transition, 14,33 emergence of vortices in superconductors, 34 vapor condensation in porous media, 35 etc.͒. While it is not obvious that these systems should show similar properties, they share a common characteristic of being spatially extended, with a complex free energy landscape.…”

“…12 Prototypical solidsolid phase transitions with associated AE are martensitic transitions, for which the analysis of the AE has provided valuable information on the mechanisms and kinetics of the transition. [12][13][14][15][16] The mechanisms of the crystallographic change in Gd 5 ͑Si x Ge 1−x ͒ 4 involve shearing of planes perpendicular to the long b axis. 6,17 Since this mechanism shares some similarities with martensitic transitions, it has been termed "martensiticlike."…”

Random-Field Ising Models of Hysteresis

“…Experimental studies of the acoustic emission generated during a thermally induced martensitic transformation of a Cu-Zn-Al single crystal revealed an apparent absence of characteristic scales in the distribution of avalanches (174). After an initial number of hysteresis cycles (ramping temperature) the system reaches a final attractor yielding two decades of power law scaling in the time distribution of acoustic emission pulse durations.…”

Finite-size scaling analysis of the avalanches in the three-dimensional Gaussian random-field Ising model with metastable dynamics

“…This framework, which has sometimes been called fluctuationless firstorder phase transitions, 1,2 is one of the basic mechanisms responsible for power laws in nature. 3 Experimental examples have been found in a broad set of physical systems: magnetic transitions, 4 adsorption, 5 superconductivity, 6 martensitic transformations, 7 etc.…”