Critical Slowing Down at the Abrupt Mott Transition: When the First-Order Phase Transition Becomes Zeroth Order and Looks Like Second Order

Abstract

We report that the thermally-induced Mott transition in vanadium sesquioxide shows criticalslowing-down and enhanced variance ('critical opalescence') of the order parameter fluctuations measured through low-frequency resistance-noise spectroscopy. Coupled with the observed increase of also the phase-ordering time, these features suggest that the strong abrupt transition is controlled by a critical-like singularity in the hysteretic metastable phase. The singularity is identified with the spinodal point and is a likely consequence of the strain-induced long-range-interaction.

Asymmetric magnetic relaxation behavior of domains and domain walls observed through the FeRh first-order metamagnetic phase transition

“…Little is known about the regions between phases in systems that exhibit first-order phase transitions but it is clear from this work that it plays a role in the dynamic behavior. Given there are many ways that two states in a first-order phase transition system can couple across the boundary including elastic coupling due to strain 8,27 , magnetic coupling in metamagnetic transitions 32,54 , and charge coupling in metal-insulator systems 4,6 , it may be that this influence of the coupling across the phase boundary can be seen to a↵ect a variety of di↵erent firstorder phase transition systems. This work highlights that the influence of interphase coupling should be considered in theories of first-order phase transition dynamics when interested in the smaller scale behavior, as well as demonstrating that the phase boundary wall to be an interesting entity in its own right which requires further study.…”

“…However, due to the presence of latent heat the same behavior is not expected through firstorder phase transitions 1 . As such, the dynamics of firstorder phase transitions are not as well understood and so remain a topic of active investigation [4][5][6][7][8] . Recent breakthroughs in imaging techniques, capable of tracking various material properties, has led to a surge of interest in materials that exhibit first-order phase transitions 4,6,7 .…”

“…They show that first-order phase transition systems demonstrate critical scaling behavior of both the domain size 4,7 , and the phase boundary wall 4,6 , which acts to blur the once definitive line between the two phase transition classifications. The coupling between regions of the two phases is cited as the source of this quasi-second-order behavior [4][5][6][7][8] .…”

“…Another interesting aspect of phase transition dynamics is their temporal relaxation behavior 3,8,9 . Recently, quasi-second-order behavior has been observed in the phase-ordering and relaxation times in a Mott insulatormetal transition system 8 . Despite this wave of recent interest in first-order phase transition dynamics, the role of the phase boundary wall in these proceedings remains unclear.…”

Zeroth-Order Nucleation Transition under Nanoscale Phase Separation

“…Metal-insulator phase transitions in some materials, such as V 2 O 3 , were classified as zeroth-order phase transitions, where the free energy is discontinuous [21,22]. These phase transitions exhibit the phase coexistence and ramified fractal-like nanoscale phase separation in the transition region [21][22][23].…”