Dispersion analysis and measurement of potassium tantalate niobate crystals by broadband optical interferometers.

See more Niobium products. Niobium (atomic symbol: Nb, atomic number: 41) is a Block D, Group 5, Period 5 element with an atomic weight of 92.90638. The number of electrons in each of niobium's shells is 2, 8, 18, 12, 1 and its electron configuration is [Kr] 4d⁴ 5s¹. The niobium atom has a radius of 146 pm and a Van der Waals radius of 207 pm. Niobium was discovered by Charles Hatchett in 1801 and first isolated by Christian Wilhelm Blomstrand in 1864. In its elemental form, niobium has a gray metallic appearance. Niobium has the largest magnetic penetration depth of any element and is one of three elemental type-II superconductors (along with vanadium and technetium). Niobium is found in the minerals pyrochlore, its main commercial source, and columbite. The word Niobium originates from Niobe, daughter of mythical Greek king Tantalus.

See more Potassium products. Potassium (atomic symbol: K, atomic number: 19) is a Block S, Group 1, Period 4 element with an atomic weight of 39.0983. The number of electrons in each of Potassium's shells is [2, 8, 8, 1] and its electron configuration is [Ar] 4s¹. The potassium atom has a radius of 227.2 pm and a Van der Waals radius of 275 pm. Potassium was discovered and first isolated by Sir Humphrey Davy in 1807. Potassium is the seventh most abundant element on earth. It is one of the most reactive and electropositive of all metals and rapidly oxidizes. As with other alkali metals, potassium decomposes in water with the evolution of hydrogen because of its reacts violently with water, it only occurs in nature in ionic salts. In its elemental form, potassium has a silvery gray metallic appearance, but its compounds (such as potassium hydroxide) are more frequently used in industrial and chemical applications. The origin of the element's name comes from the English word 'potash,' meaning pot ashes, and the Arabic word qali, which means alkali. The symbol K originates from the Latin word kalium.

See more Tantalum products. Tantalum (atomic symbol: Ta, atomic number: 73) is a Block D, Group 5, Period 6 element with an atomic weight of 180.94788. The number of electrons in each of tantalum's shells is [2, 8, 18, 32, 11, 2] and its electron configuration is [Xe] 4f¹⁴ 5d³ 6s². The tantalum atom has a radius of 146 pm and a Van der Waals radius of 217 pm. Tantalum was first discovered by Anders G. Ekeberg in 1802 in Uppsala, Sweden however, it was not until 1844 when Heinrich Rose first recognized it as a distinct element. In its elemental form, tantalum has a grayish blue appearance. Tantalum is found in the minerals tantalite, microlite, wodginite, euxenite, and polycrase. Due to the close relation of tantalum to niobium in the periodic table, Tantalum's name originates from the Greek word Tantalos meaning Father of Niobe in Greek mythology.