Rare earth-doped barium gallo-germanate glasses and their near-infrared luminescence properties.

See more Barium products. Barium (atomic symbol: Ba, atomic number: 56) is a Block S, Group 2, Period 6 element with an atomic weight of 137.27. The number of electrons in each of barium's shells is [2, 8, 18, 18, 8, 2] and its electron configuration is [Xe] 6s². Barium is a member of the alkaline-earth metals. The barium atom has a radius of 222 pm and a Van der Waals radius of 268 pm. Barium was discovered by Carl Wilhelm Scheele in 1772 and first isolated by Humphry Davy in 1808. In its elemental form, barium is a soft, silvery-gray metal. Industrial applications for barium include acting as a "getter," or unwanted gas remover, for vacuum tubes, and as an additive to steel and cast iron. Barium is also alloyed with silicon and aluminum in load-bearing alloys. The main commercial source of barium is the mineral barite (BaSO₄); it does not occur naturally as a free element . The name barium is derived from the Greek word "barys," meaning heavy.

See more Gallium products. Gallium (atomic symbol: Ga, atomic number: 31) is a Block P, Group 13, Period 4 element with an atomic weight of 69.723.The number of electrons in each of Gallium's shells is 2, 8, 18, 3 and its electron configuration is [Ar] 3d¹⁰ 4s² 4p¹. The gallium atom has a radius of 122.1 pm and a Van der Waals radius of 187 pm. Gallium was predicted by Dmitri Mendeleev in 1871. It was first discovered and isolated by Lecoq de Boisbaudran in 1875. In its elemental form, gallium has a silvery appearance. Gallium is one of three elements that occur naturally as a liquid at room temperature, the other two being mercury and cesium. Gallium does not exist as a free element in nature and is sourced commercially from bauxite and sphalerite. Currently, gallium is used in semiconductor devices for microelectronics and optics. The element name originates from the Latin word 'Gallia' referring to Gaul, the old name of France.

See more Germanium products. Germanium (atomic symbol: Ge, atomic number: 32) is a Block P, Group 14, Period 4 element with an atomic weight of 72.63. The number of electrons in each of germanium's shells is 2, 8, 18, 4 and its electron configuration is [Ar] 3d¹⁰ 4s² 4p². The germanium atom has a radius of 122.5 pm and a Van der Waals radius of 211 pm. Germanium was first discovered by Clemens Winkler in 1886. In its elemental form, germanium is a brittle grayish white semi-metallic element. Germanium is too reactive to be found naturally on Earth in its native state. It is commercially obtained from zinc ores and certain coals. It is also found in argyrodite and germanite. It is used extensively as a semiconductor in transitors, solar cells, and optical materials. Other applications include acting an alloying agent, as a phosphor in fluorescent lamps, and as a catalyst. The name Germanium originates from the Latin word "Germania" meaning "Germany."