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Tantalum pentoxide, also known as tantalum(V) oxide, is the inorganic compound with the formula Ta 2 O 5. It is a white solid that is insoluble in all solvents but is attacked by strong bases and hydrofluoric acid. Ta 2 O 5 is an inert material with a high refractive index and low absorption (i.e. colourless), which makes it useful for coatings ...
A typical tantalum capacitor is a chip capacitor and consists of tantalum powder pressed and sintered into a pellet as the anode of the capacitor, with the oxide layer of tantalum pentoxide as a dielectric, and a solid manganese dioxide electrolyte as the cathode.
Tantalum electrolytic capacitors exploit the tendency of tantalum to form a protective oxide surface layer, using tantalum powder, pressed into a pellet shape, as one "plate" of the capacitor, the oxide as the dielectric, and an electrolytic solution or conductive solid as the other "plate".
Tantalum(V) oxide films have a variety of applications including as optical films with refractive indices as high as 2.039 [16] and as a thin-film dielectric material in dynamic random access memory and semiconductor field-effect transistors. [12] The approach chosen for preparation of these materials is determined by the desired properties.
By applying a positive voltage to the above-mentioned anode material in an electrolytic bath an oxide barrier layer with a thickness corresponding to the applied voltage will be formed (formation). This oxide layer acts as the dielectric in an electrolytic capacitor. The properties of these oxide layers are given in the following table:
Its relative dielectric constant is ~22 and it has a thermal expansion coefficient of 8~10×10 −6 /K. The thermal conductivity of LSAT is 5.1 Wm −1 K −1. [2] [3] LSAT's (cubic) lattice parameter of 3.868 Å makes it compatible for the growth of a wide range of perovskite oxides with a relatively low strain. [citation needed]
The metals form different oxides: vanadium forms vanadium(II) oxide, vanadium(III) oxide, vanadium(IV) oxide and vanadium(V) oxide, niobium forms niobium(II) oxide, niobium(IV) oxide and niobium(V) oxide, but out of tantalum oxides only tantalum(V) oxide is characterized. Metal(V) oxides are generally nonreactive and act like acids rather than ...
Niobium is a sister metal to tantalum. Niobium has a similar melting point (2744 °C) to tantalum and exhibits similar chemical properties. The materials and processes used to produce niobium-dielectric capacitors are essentially the same as for existing tantalum-dielectric capacitors.