Resistivity of V2O3 thin films deposited on a-plane (110) and c-plane (001) sapphire by pulsed laser deposition

Abstract

Thin films of V 2 O 3 with thickness of 215 nm were grown on a-and c-plane sapphire by pulsed laser deposition with ͑001͒V 2 O 3 ʈ ͑001͒Al 2 O 3 and ͑110͒V 2 O 3 ʈ ͑110͒Al 2 O 3 epitaxy. The effects of the growth direction on the electrical resistivity of the films were examined. Films on c-plane sapphire displayed a metal-to-insulator transition at T = 180 K compared to T = 160 K in single-crystal V 2 O 3 . The films on a-plane sapphire, however, showed an insulator-to-insulator transition at T = 186 K. The variation in the phase transformation characteristics and the resistivity can be attributed to different levels of strain and commensurate changes in the film morphology.

Facile synthesis and phase transition of V2O3 nanobelts

“…The phase transition temperature was estimated to be ~150 K by taking the maximum in the derivative of the resistivity plot. [14] The measured Tc of V2O3 nanobelts was similar to that of the bulk materials and thin films of V2O3, [5,14] indicating that the width of the nanobelt (~100 nm) was still above the critical size of V2O3 to show obvious quantum fluctuations.…”

“…[15,17] To further explore the phase transition of the V2O3 nanobelts, we also utilized variable-temperature Raman spectroscopy (VT-Raman) to measure the Tc of individual V2O3 nanobelts. Compared to other methods such as variable-temperature XRD, [9] optical [18] and electrical measurements, [14] VT-Raman is capable of detecting individual material with high spatial resolution and does not require complicated lithographic fabrications. So this method was widely used to trace the phase transition of low dimensional materials [19] , including V2O3 [20,21] We first measured the Raman spectra of V2O3 nanobelts sitting on 300 nm SiO2/Si substrates in vacuum at room temperature by mapping a few V2O3 nanobelts (Fig.…”

Epitaxial growth and metal-insulator transition of vanadium oxide thin films with controllable phases

“…For the V 2 O 3 film, the values of T c and DH are very close to the previous study. 4,17 The values of DT (average about 10 K) and DH (28 K) is related to the large residual stress in the V 2 O 3 thin films as described by Clausius-Clapeyron equation. 18 Due to the lattice and thermal mismatch between the film and the substrate, the typical strain in our V 2 O 3 films is as large as À7.3%.…”

Фазовый Переход Металл-Диэлектрик В Гидрированных Тонких Пленках v-=sub=-2-=/Sub=-O-=sub=-3-=/Sub=-

“…Последнее обстоятельство приводит к растрескива-нию монокристаллических образцов [6,7]. Это означает, что для практического применения этого материала большими функциональными возможностями обладают тонкие пленки, которые интенсивно изучаются в послед-ние годы [8][9][10][11]. Существенное влияние на температуру и характер фазового перехода оказывает легирование и всестороннее сжатие [4].…”