Electro-Physical Properties of Niobia Columnlike Nanostructures via the Anodizing of Al/Nb Layers

Abstract

Two types of niobia columnlike nanostructures were synthesized by anodization, reanodization, and chemical etching of sputter-deposited Al/Nb metal layers. The morphological properties of synthesized niobia columnlike nanostructures were determined by means of scanning electron microscopy. The electro-physical characteristics of niobia columnlike nanostructures were investigated in two measurement schemes. Aluminum layers of thickness 500 nm were used as contact pads. The current-voltage I-U characteristic has a nonlinear and nonsymmetrical character. The rising of temperature leads to an increase of the current. This behavior may indicate a p-n or metal-semiconductor junction. The initial resistance at 23 o C was 60 and 120 kOhms, the specific resistance to the height of the columns was 87 and 116 kOhms•nm -1 , the calculated temperature coefficient of resistance appeared to be negative and rather low: -1.39×10 -2 and -1.28×10 -2 K -1 for the niobia columnlike nanostructures reanodized at 300 and 450 V, respectively.

Столбиковые Ниобиевые Оксидные Наноструктуры: Механизм Образования, Микроструктура И Электрофизические Свойства

“…При обратном включении управляющие напряжения при максимальном токе примерно на 5 V были ниже, чем в прямом. Таким образом, характер токовой зависимости определяется как контактными явлениями на верxнем и нижнем контактах, так и неоднородностью распределения носителей заряда в самих столбиках [29].…”

Anodizing Tungsten Foil with Ionic Liquids for Enhanced Photoelectrochemical Applications

“…Some other methods have been studied to create WO 3 nanostructures with a wide variety of morphologies (nanowires, nanopores, nanoflakes, nanoplates, etc.) such as hydrothermal methods [ 9 ], solvothermal methods [ 10 ], deposition processes (laser deposition [ 11 ], sol–gel [ 12 ], electrodeposition [ 13 , 14 ], chemical vapor deposition [ 15 ], RF sputtering [ 16 , 17 ], spin-coating [ 18 ]), and combustion. However, they use corrosive reactants and large amounts of energy and they are more complex to operate in comparison with anodization techniques.…”

Facile Synthesis of Ag-Doped Urchin-like MnO2 on Carbon Cloth for Supercapacitors

“…Many high-performance supercapacitors have been developed using transition metal compounds with nanostructures [ 10 ], such as aluminum oxide [ 11 ], niobium oxide [ 12 ], iron oxide [ 13 ], etc. As a typical representative of pseudocapacitive materials, MnO 2 has attracted great attention as a good candidate for electrode materials owing to its rich sources, low price, and excellent electrochemical performance (theoretical specific capacitance of 1370 F/g) [ 14 , 15 ].…”