Suppression of Structural Phase Transition in VO2 by Epitaxial Strain in Vicinity of Metal-insulator Transition

Mechanism of metal-insulator transition (MIT) in strained VO2 thin films is very complicated and incompletely understood despite three scenarios with potential explanations including electronic correlation (Mott mechanism), structural transformation (Peierls theory) and collaborative Mott-Peierls transition. Herein, we have decoupled coactions of structural and electronic phase transitions across the MIT by implementing epitaxial strain on 13-nm-thick (001)-VO2 films in comparison to thicker films. The structural evolution during MIT characterized by temperature-dependent synchrotron radiation high-resolution X-ray diffraction reciprocal space mapping and Raman spectroscopy suggested that the structural phase transition in the temperature range of vicinity of the MIT is suppressed by epitaxial strain. Furthermore, temperature-dependent Ultraviolet Photoelectron Spectroscopy (UPS) revealed the changes in electron occupancy near the Fermi energy EF of V 3d orbital, implying that the electronic transition triggers the MIT in the strained films. Thus the MIT in the bi-axially strained VO2 thin films should be only driven by electronic transition without assistance of structural phase transition. Density functional theoretical calculations further confirmed that the tetragonal phase across the MIT can be both in insulating and metallic states in the strained (001)-VO2/TiO2 thin films. This work offers a better understanding of the mechanism of MIT in the strained VO2 films.

[1]  Nicholas D M Hine,et al.  Vanadium dioxide: a Peierls-Mott insulator stable against disorder. , 2012, Physical review letters.

[2]  S. Parkin,et al.  Suppression of Metal-Insulator Transition in VO2 by Electric Field–Induced Oxygen Vacancy Formation , 2013, Science.

[3]  Sun Jin Yun,et al.  Micrometer x-ray diffraction study of VO 2 films: Separation between metal-insulator transition and structural phase transition , 2008 .

[4]  Kunio Okimura,et al.  Characterization of structural dynamics of VO2 thin film on c-Al2O3 using in-air time-resolved x-ray diffraction , 2010 .

[5]  R. Lukaszew,et al.  Effect of a substrate-induced microstructure on the optical properties of the insulator-metal transition temperature in VO2 thin films , 2013 .

[6]  Yunhui Huang,et al.  VO2/TiO2 Nanosponges as Binder-Free Electrodes for High-Performance Supercapacitors , 2015, Scientific Reports.

[7]  Xiaoguang Li,et al.  Surface-growth-mode-induced strain effects on the metal–insulator transition in epitaxial vanadium dioxide thin films , 2015 .

[8]  S. Wolf,et al.  THz spectroscopy of VO2 epitaxial films: controlling the anisotropic properties through strain engineering , 2012 .

[9]  Hubbard gap modulation in vanadium dioxide nanoscale tunnel junctions. , 2014, Nano letters.

[10]  Liuming Yan,et al.  The modulation of metal–insulator transition temperature of vanadium dioxide: a density functional theory study , 2014 .

[11]  Matthew D. Pickett,et al.  Sequential Electronic and Structural Transitions in VO2 Observed Using X‐ray Absorption Spectromicroscopy , 2014, Advanced materials.

[12]  Gyungock Kim,et al.  Raman study of electric-field-induced first-order metal-insulator transition in VO2-based devices , 2005 .

[13]  Shriram Ramanathan,et al.  Terahertz spectroscopy studies on epitaxial vanadium dioxide thin films across the metal-insulator transition. , 2011, Optics letters.

[14]  John B. Goodenough,et al.  The two components of the crystallographic transition in VO2 , 1971 .

[15]  Shik Shin,et al.  Band dispersion near the Fermi level for VO2 thin films grown on TiO2 (001) substrates , 2009 .

[16]  Hidekazu Tanaka,et al.  Interface effect on metal-insulator transition of strained vanadium dioxide ultrathin films , 2007 .

[17]  Byung-Gyu Chae,et al.  Mott Transition in VO2 Revealed by Infrared Spectroscopy and Nano-Imaging , 2007, Science.

[18]  Xiang-Bai Chen.  Assignment of the Raman Modes of VO_2 in the Monoclinic Insulating Phase , 2011 .

[19]  Stuart A. Wolf,et al.  Large epitaxial bi-axial strain induces a Mott-like phase transition in VO2 , 2014 .

[20]  P. Schilbe.  Raman scattering in VO2 , 2002 .

[21]  J. W. Matthews,et al.  Defects in epitaxial multilayers: I. Misfit dislocations* , 1974 .

[22]  Y. Muraoka,et al.  Photoemission study of the metal-insulator transition inVO2/TiO2(001): Evidence for strong electron-electron and electron-phonon interaction , 2004 .

[23]  Jinzhong Zhang,et al.  Manipulations from oxygen partial pressure on the higher energy electronic transition and dielectric function of VO2 films during a metal–insulator transition process , 2015 .

[24]  Yong-Sik Lim,et al.  Observation of First-Order Metal-Insulator Transition without Structural Phase Transition in VO_2 , 2004, cond-mat/0402485.

[25]  F Venturini,et al.  Transfer of spectral weight and symmetry across the metal-insulator transition in VO(2). , 2006, Physical review letters.

[26]  Ziyu Wu,et al.  Decoupling the Lattice Distortion and Charge Doping Effects on the Phase Transition Behavior of VO2 by Titanium (Ti4+) Doping , 2015, Scientific Reports.

[27]  H. Bandulet,et al.  Phase diagram of the ultrafast photoinduced insulator-metal transition in vanadium dioxide , 2012 .

[28]  Claudia Felser,et al.  Distinct electronic structure of the electrolyte gate-induced conducting phase in vanadium dioxide revealed by high-energy photoelectron spectroscopy. , 2014, ACS Nano.

[29]  Shriram Ramanathan,et al.  Suspended sub-50 nm vanadium dioxide membrane transistors: fabrication and ionic liquid gating studies. , 2012, Nanoscale.

[30]  Gabriel Kotliar,et al.  Effects of strain on the electronic structure of VO_2 , 2010, 1005.0886.

[31]  Jamie M Booth,et al.  Anisotropic structure deformation in the VO2 metal-insulator transition. , 2009, Physical review letters.

[32]  A. Zakharov,et al.  Direct observation of decoupled structural and electronic transitions and an ambient pressure monocliniclike metallic phase of VO2. , 2014, Physical review letters.

[33]  Hyun-Tak Kim,et al.  Observation of Mott Transition in VO_2 Based Transistors , 2003 .

[34]  Sergei V. Kalinin,et al.  Symmetry relationship and strain-induced transitions between insulating M1 and M2 and metallic R phases of vanadium dioxide. , 2010, Nano letters.

[35]  H. Bechtel,et al.  Phase transition in bulk single crystals and thin films of VO2 by nano-infrared spectroscopy and imaging , 2015, 1506.04786.

[36]  Yuji Muraoka,et al.  Metal-insulator transition of VO2 thin films grown on TiO2 (001) and (110) substrates , 2002 .

[37]  R. Mark Wilson,et al.  Metal–insulator transition in vanadium dioxide , 2009 .

[38]  C. Zou,et al.  Strain dynamics of ultrathin VO₂ film grown on TiO₂ (001) and the associated phase transition modulation. , 2014, Nano letters.

[39]  Chang-Jong Kang,et al.  Correlation-assisted phonon softening and the orbital-selective Peierls transition in VO 2 , 2012, 1207.1770.

[40]  F. J. Morin,et al.  Oxides Which Show a Metal-to-Insulator Transition at the Neel Temperature , 1959 .

[41]  H. Bernien,et al.  Active terahertz nanoantennas based on VO2 phase transition. , 2010, Nano letters.

[42]  Angel Rubio,et al.  Instantaneous band gap collapse in photoexcited monoclinic VO2 due to photocarrier doping. , 2014, Physical review letters.

[43]  Byung-Gyu Chae,et al.  Monoclinic and correlated metal phase in VO(2) as evidence of the Mott transition: coherent phonon analysis. , 2006, Physical review letters.

[44]  J. Sakai,et al.  Temperature-dependent Raman and ultraviolet photoelectron spectroscopy studies on phase transition behavior of VO2 films with M1 and M2 phases , 2014 .

[45]  Gyungock Kim,et al.  Mechanism and observation of Mott transition in VO2-based two- and three-terminal devices , 2004 .

[46]  Yinchang Zhao,et al.  Anomalous thickness-dependent strain states and strain-tunable magnetization in Zn-doped ferrite epitaxial films , 2014 .

[47]  Ziyu Wu,et al.  Understanding the nature of the kinetic process in a VO2 metal-insulator transition. , 2010, Physical review letters.

[48]  D. Muller,et al.  Nature of the metal insulator transition in ultrathin epitaxial vanadium dioxide. , 2013, Nano letters.

[49]  Hongkun Park,et al.  Strain-induced self organization of metal-insulator domains in single-crystalline VO2 nanobeams. , 2006, Nano letters.

[50]  Mohamed Chaker,et al.  A photoinduced metal-like phase of monoclinic VO2 revealed by ultrafast electron diffraction , 2014, Science.

[51]  Shriram Ramanathan,et al.  Correlation between metal-insulator transition characteristics and electronic structure changes in vanadium oxide thin films , 2008 .

[52]  Xiaoguang Li,et al.  Resistance switching of epitaxial VO2/Al2O3 heterostructure at room temperature induced by organic liquids , 2015 .

[53]  Tohru Suemoto,et al.  Photoinduced metallic state in VO2 proved by the terahertz pump-probe spectroscopy , 2008 .

[54]  허윤석.  In situ probing of doping- and stress-mediated phase transitions in a single-crystalline VO2 nanobeam by spatially resolved Raman spectroscopy , 2014 .

[55]  S. A. Wolf,et al.  Photoemission evidence for crossover from Peierls-like to Mott-like transition in highly strained VO2 , 2012 .

[56]  H. Ohashi,et al.  Photoemission evidence for a Mott-Hubbard metal-insulator transition inVO2 , 2008 .

[57]  John B. Shoven,et al.  I , Edinburgh Medical and Surgical Journal.

[58]  Tong-Yi Zhang,et al.  Strain relaxation in heteroepitaxial films by misfit twinning: II. Equilibrium morphology , 2007 .

[59]  Stuart S. P. Parkin,et al.  Control of the metal–insulator transition in vanadium dioxide by modifying orbital occupancy , 2013, Nature Physics.

[60]  M. Goldflam,et al.  Anisotropic electronic state via spontaneous phase separation in strained vanadium dioxide films. , 2013, Physical review letters.

[61]  Byung-Gyu Chae,et al.  Memory Metamaterials , 2009, Science.

[62]  Lei Dai,et al.  VO2 thermochromic smart window for energy savings and generation , 2013, Scientific Reports.

[63]  Yandong Gong,et al.  Switchable Ultrathin Quarter-wave Plate in Terahertz Using Active Phase-change Metasurface , 2015, Scientific Reports.