Interplay between Ferroelastic and Metal−Insulator Phase Transitions in Strained Quasi-Two-Dimensional VO 2 Nanoplatelets
2010; American Chemical Society; Volume: 10; Issue: 6 Linguagem: Inglês
10.1021/nl1008794
ISSN1530-6992
AutoresAlexander Tselev, Evgheni Strelcov, Igor Lukyanchuk, J. D. Budai, Jonathan Z. Tischler, Ilia N. Ivanov, K. M. Jones, Roger Proksch, Sergei V. Kalinin, Andrei Kolmakov,
Tópico(s)Multiferroics and related materials
ResumoFormation of ferroelastic twin domains in vanadium dioxide (VO(2)) nanosystems can strongly affect local strain distributions, and hence couple to the strain-controlled metal-insulator transition. Here we report polarized-light optical and scanning microwave microscopy studies of interrelated ferroelastic and metal-insulator transitions in single-crystalline VO(2) quasi-two-dimensional (quasi-2D) nanoplatelets (NPls). In contrast to quasi-1D single-crystalline nanobeams, the 2D geometric frustration results in emergence of several possible families of ferroelastic domains in NPls, thus allowing systematic studies of strain-controlled transitions in the presence of geometrical frustration. We demonstrate the possibility of controlling the ferroelastic domain population by the strength of the NPl-substrate interaction, mechanical stress, and by the NPl lateral size. Ferroelastic domain species and domain walls are identified based on standard group-theoretical considerations. Using variable temperature microscopy, we imaged the development of domains of metallic and semiconducting phases during the metal-insulator phase transition and nontrivial strain-driven reentrant domain formation. A long-range reconstruction of ferroelastic structures accommodating metal-insulator domain formation has been observed. These studies illustrate that a complete picture of the phase transitions in single-crystalline and disordered VO(2) structures can be drawn only if both ferroelastic and metal-insulator strain effects are taken into consideration and understood.
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