Single-shot time resolved study of the photo-reversible phase transition induced in flakes of Ti3O5 nanoparticles at room temperature

Abstract

We have performed single-shot time-resolved reflectivity measurements of the photo-reversible phase transition between k-and b-phases of Ti 3 O 5 nanoparticles at room temperature. These phase transitions are induced using nanosecond and millisecond laser pulses and are revealed by Raman spectroscopy. Upon nanosecond pulsed excitation, the k-to b-phase transition is detected in about 900 ns, whereas the b-to k-phase transition is noticed in less than 20 ns. The k-to b-phase transition induced by quasi continuous wave laser happens on the millisecond time scale. We propose a scenario that accounts very well for the observed phenomena.

Time‐Resolved X‐Ray Powder Diffraction Study of Photoinduced Phase Transitions in Ti3O5 Nanoparticles

“…This suggestst hat light-induced phase transformationso fT i 3 O 5 nanoparticles may be promising for technological applications. [17] The results reporteds of ar suggest that light-inducedp hase transformationso fT i 3 O 5 nanoparticles may be promising for technological applications. The results show ap artial structuralc hange, limited by differences betweenp umped and probedv olumes, which persists af ew microseconds after excitation.…”

“…Their results suggest that the phase transition from l-Ti 3 O 5 to b-Ti 3 O 5 is dependent on the duration of the excitation pulses and, on this timescale (ns), originates from laser-induced heatinga nd shock waves. [17] The results reporteds of ar suggest that light-inducedp hase transformationso fT i 3 O 5 nanoparticles may be promising for technological applications. [5,[15][16][17] Several important questions, however, remain.…”

“…[15] The dynamics of the photoinduced phase transition by using time-resolved (TR) diffuse reflectivity was observed at room temperature in b-Ti 3 O 5 nanoparticles on aw ide range of timescales. [16,17] In the work of Asahara et al,afast drop in reflectivity was observed within af ew hundreds of femtoseconds, followed by ap artial recovery within 1ps. This behavior was interpreted as an on-thermal, transient phase transition from the b-phasetothe l-phase.…”

“…The new phase, dubbed l-Ti 3 O 5 ,h as am onoclinic structure and belongs to the space group C2/m with an electrical conductivity value of about 30 Scm À1 .T his new phase is am etastable state at room temperature. [16,17] In the work of Asahara et al,afast drop in reflectivity was observed within af ew hundreds of femtoseconds, followed by ap artial recovery within 1ps. This suggestst hat light-induced phase transformationso fT i 3 O 5 nanoparticles may be promising for technological applications.…”

“…Here, we report ap hotoinduceds emiconductor-to-metal phase transition from b-Ti 3 O 5 to l-Ti 3 O 5 nanoparticles at room temperature observed directly by time-resolved X-ray powder diffraction in ap ump-probe setup. [5,[15][16][17] Several important questions, however, remain. The first step in the relaxation back to the ground state can be described by as ingle exponential decay with time constant within microsecond timescales.…”