Discrete β-Ta2O5 crystallite formation in reactively sputtered amorphous thin films

Tantalum Suboxide Films with Tunable Composition and Electrical Resistivity Deposited by Reactive Magnetron Sputtering

“…This observation of the lack of crystallinity is consistent across all O levels, including stoichiometric Ta 2 O 5 , indicating that the presence of O suppresses crystallization in these films. For the limiting case of stoichiometric Ta 2 O 5 , these findings are in agreement with previous reports that either high substrate temperatures ( 450 • C) or post-deposition annealing above ∼600-900 • C is required for crystallization of sputter-deposited Ta 2 O 5 films [12,[16][17][18]. The present work shows that crystallinity is not observed even for substoichiometric TaO x films with O content down to at least 46 at.%, likely as a result of the low substrate temperature during deposition.…”

“…Tantalum oxides are, therefore, attractive candidates as alternative hohlraum materials due to their tunable electrical resistivity and good oxidation and corrosion resistance. Prior work on the Ta-O system has mostly focused on stoichiometric Ta 2 O 5 films [10][11][12] or else films with oxygen content in the range of 0-60 at.% [13,14]. Films with composition corresponding to the transition from metallic conduction to insulating behavior remain comparatively unexplored.…”

“…In recent years, Ta 2 O 5 has also received attention for optical applications due to the emergence of broad photoluminescence peaks that can be tuned through the controlled introduction of dopants [10] and as a surface protective coating with applications across materials for harsh environments and biocompatibility [15]. In light of this wide range of applications, a detailed study of reactive magnetron sputtering across a range of oxide compositions is timely, to complement existing research involving post-deposition annealing [12,[16][17][18][19]. In particular, reactive sputter deposition enables much greater control of oxygen content by matching Ta and O availability during deposition and can be used to fabricate films with uniform properties through film thickness and over the substrate area.…”

Sub-10-nm Mixed Titanium/Tantalum Oxide Nanoporous Films with Visible-Light Photocatalytic Activity for Water Treatment

“…% Ta can be evidenced from the observation of peaks appearing at 27.4°, 54.3°, and 56.6°, corresponding to the (110), (211), and (220) crystal planes, respectively. The limited crystallinity concerning Ta 2 O 5 is in good agreement with previous reports, where partial crystallization could be obtained below 500 °C or up to 600 °C . Partial crystallization of Ta 2 O 5 can be observed from Figure S9, with the presence of (200) and (221) planes at 32.7° and the (200) plane from TaO suboxide at 31.8° (ICDD: 04-007-0866).…”

“…The limited crystallinity concerning Ta 2 O 5 is in good agreement with previous reports, where partial crystallization could be obtained below 500 °C45 or up to 600 °C. 46 Partial crystallization of Ta 2 O 5 can be observed from Figure S9, with the presence of (200) and (221) planes at 32.7°and the (200) plane from TaO suboxide at 31.8°( ICDD: 04-007-0866).…”