Crystal structure development of vanadium oxide thin films deposited by a magnetron sputtering technique

Abstract

Articles you may be interested inMicrostructural evolution of thin film vanadium oxide prepared by pulsed-direct current magnetron sputtering J. Appl. Phys. 112, 093504 (2012); 10.1063/1.4759255 Enhanced electrical and noise properties of nanocomposite vanadium oxide thin films by reactive pulsed-dc magnetron sputtering Appl. Phys. Lett. 100, 262108 (2012); 10.1063/1.4731240 Process-structure-property correlations in pulsed dc reactive magnetron sputtered vanadium oxide thin films J. Vac. Sci. Technol. A 29, 061504 (2011); 10.1116/1.3636372 Growth, electrical, and optical properties of nanocrystalline VO 2 (011) thin films prepared by thermal oxidation of magnetron sputtered vanadium films J. Vac. Sci. Technol. A 28, 595 (2010); 10.1116/1.3443562Vanadium oxide thin films for bolometric applications deposited by reactive pulsed dc sputtering Crystal structure of vanadium oxide films with different thickness, deposited on glass and F:SnO 2 coated (FTO) substrates, was studied. It was found that all the films annealed at 450 C developed a metastable b-V 2 O 5 monoclinic crystal structure, represented by crystals of up to 100 nm. At higher temperatures, the original crystals of relatively thick films of 400 nm on the glass substrate first increased in size and improved their crystal structure symmetry from the monoclinic to tetragonal, then gradually intergrew into spectacular superstructures of crystal "leaves" (500 C) and "needles" (550 C). Thin films of 130 nm exhibited a similar crystallization processes but at a higher rate. It was found that the FTO substrate supported the slowest crystal growth dynamics with annealing temperature. The original crystals did not grow in size and retained their low b monoclinic symmetry in the whole temperature range up to 550 C. The superstructure appeared around film imperfections in the form of plate macroscopic crystals with improved tetragonal symmetry, and it covered only one third of the film surface. The metastable b phase growth and its development were discussed and explained in terms of the combined effect of high crystal/substrate surface tension and crystal surface energy.

Influence of the rf power and oxygen content on structural, electrical, and optical properties of V2O5 thin films prepared via reactive radio frequency sputtering

“…26-1165 for monoclinic β-V 2 O 5 (βм-V 2 O 5 ). In addition, the experimental crystallographic pattern obtained from the film at 10% O 2 and 150 W RF power is in good agreement with those of results reported by Asadov et al [14].…”

“…The metastable β-V 2 O 5 phase can be prepared using physical techniques, especially sputtering; however, it is formed by post-annealing at high temperatures [12,13]. The β-V 2 O 5 structure composed of monoclinic (βм) and tetragonal (βт) symmetries was first reported by Asadov et al [14], who proposed that the films deposited by direct current (DC) magnetron sputtering with a V 2 O 5 target exhibited phase transitions between βм and βт symmetries after post-annealing at temperatures >500 °C. This structure responds intensely to temperature-sensitive crystallization processes because of its layered structure and this phase is built of VO 6 octahedra linked in layers through shared common edges and corners, and the series of layers interact via weak van der Waals interactions of the vanadium-oxygen bond [8].…”

Structural control of V2O5 nanoparticles via a thermal decomposition method for prospective photocatalytic applications

“…V 2 O 4 ) [6]. Owing to its saturated oxidation state (V +5 ), Vanadium pentoxide (V 2 O 5 ) is the main stable compound in these oxidation groups [7]. Owing to its structure, V 2 O 5 has been incorporated into many applications, including solar cells, optical, and electrical devices [8,9].…”

“…α-V 2 O 5 (Orthorhombic), β-V 2 O 5 (tetragonal or monoclinic), and γ-V 2 O 5 (Orthorhombic) are some of the polymorphs of V 2 O 5 [10]. Orthorhombic α-V 2 O 5 is the most stable phase at ambient conditions [11], whereas the β and γ phases are metastable [7]. V 2 O 5 has recently gained significant attention due to its unique features, such as catalytic activity, outstanding semiconducting, and electrochemical qualities.…”