Preparation of Ho(3+)/Tm(3+) Co-doped Lanthanum Tungsten Germanium Tellurite Glass Fiber and Its Laser Performance for 2.0??m.

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."

See more Holmium products. Holmium (atomic symbol: Ho, atomic number: 67) is a Block F, Group 3, Period 6 element with an atomic radius of 164.93032. The number of electrons in each of Holmium's shells is [2, 8, 18, 29, 8, 2] and its electron configuration is [Xe] 4f¹¹ 6s². The holmium atom has a radius of 176 pm and its Covalent radius is 192±7 pm. Holmium was first discovered by Marc Delafontaine in 1878. In its elemental form, holmium has a silvery white appearance. It is relatively soft and malleable. It is stable in dry air at room temperature but rapidly oxidizes at elevated temperatures and in moist air. Holmium has unusual magnetic properties. Its name is derived from the Latin word Holmia meaning Stockholm.

See more Lanthanum products. Lanthanum (atomic symbol: La, atomic number: 57) is a Block F, Group 3, Period 6 element with an atomic weight of 138.90547. The number of electrons in each of lanthanum's shells is [2, 8, 18, 18, 9, 2] and its electron configuration is [Xe] 5d¹ 6s². The lanthanum atom has a radius of 187 pm and a Van der Waals radius of 240 pm. Lanthanum was first discovered by Carl Mosander in 1838. In its elemental form, lanthanum has a silvery white appearance. It is a soft, malleable, and ductile metal that oxidizes easily in air. Lanthanum is the first element in the rare earth or lanthanide series. It is the model for all the other trivalent rare earths and it is the second most abundant of the rare earths after cerium. Lanthanum is found in minerals such as monazite and bastnasite. The name lanthanum originates from the Greek word Lanthaneia, which means 'to lie hidden'.

See more Tellurium products. Tellurium (atomic symbol: Te, atomic number: 52) is a Block P, Group 16, Period 5 element with an atomic radius of 127.60. The number of electrons in each of tellurium's shells is 2, 8, 18, 18, 6 and its electron configuration is [Kr] 4d¹⁰ 5s² 5p⁴. Tellurium was discovered by Franz Muller von Reichenstein in 1782 and first isolated by Martin Heinrich Klaproth in 1798. In its elemental form, tellurium has a silvery lustrous gray appearance. The tellurium atom has a radius of 140 pm and a Van der Waals radius of 206 pm. Tellurium is most commonly sourced from the anode sludges produced as a byproduct of copper refining. The name Tellurium originates from the Greek word Tellus, meaning Earth.

See more Thulium products. Thulium (atomic symbol: Tm, atomic number: 69) is a Block F, Group 3, Period 6 element with an atomic weight of 168.93421. The number of electrons in each of Thulium's shells is [2, 8, 18, 31, 8, 2] and its electron configuration is [Xe]4f¹³6s². The thulium atom has a radius of 176 pm and a Van der Waals radius of 227 pm. In its elemental form, thulium has a silvery-gray appearance. Thulium is representative of the other lanthanides (rare earths) and similar in chemistry to yttrium. It is the least abundant of the rare earth elements. Thulium emits blue upon excitation, and is used in flat panel screens that depend critically on bright blue emitters. Thulium was discovered and first isolated by Per Teodor Cleve in 1879. It is named after "Thule," which is the ancient name of Scandinavia.

See more Tungsten products. Tungsten (atomic symbol: W, atomic number: 74) is a Block D, Group 6, Period 6 element with an atomic weight of 183.84. The number of electrons in each of tungsten's shells is [2, 8, 18, 32, 12, 2] and its electron configuration is [Xe] 4f¹⁴ 5d⁴ 6s². The tungsten atom has a radius of 139 pm and a Van der Waals radius of 210 pm. Tungsten was discovered by Torbern Bergman in 1781 and first isolated by Juan José Elhuyar and Fausto Elhuyar in 1783. In its elemental form, tungsten has a grayish white, lustrous appearance. Tungsten has the highest melting point of all the metallic elements and a density comparable to that or uranium or gold and about 1.7 times that of lead. Tungsten alloys are often used to make filaments and targets of x-ray tubes. It is found in the minerals scheelite (CaWO₄) and wolframite [(Fe,Mn)WO₄]. In reference to its density, Tungsten gets its name from the Swedish words tung and sten, meaning heavy stone.