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A lanthanum hexaboride hot cathode. Lanthanum hexaboride cathodes. Lanthanum hexaboride powdered. Lanthanum hexaboride (La B 6, also called lanthanum boride and LaB) is an inorganic chemical, a boride of lanthanum. It is a refractory ceramic material that has a melting point of 2210 °C, and is insoluble in water and hydrochloric acid. [1]
Lanthanum is a chemical element with the symbol La and the atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air. It is the eponym of the lanthanide series, a group of 15 similar elements between lanthanum and lutetium in the periodic table, of which
The term derives from lanthanum, first discovered in 1838, at that time a so-called new rare-earth element "lying hidden" or "escaping notice" in a cerium mineral, [12] and it is an irony that lanthanum was later identified as the first in an entire series of chemically similar elements and gave its name to the whole series.
The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), [1] are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals. Compounds containing rare ...
lanthanum aluminate: 71496–78–1 LaB 6: lanthanum boride: 12008–21–8 LaBr 3: lanthanum bromide: 13536–79–3 La(CHO 2) 3: lanthanum formate: 2081–11–0 LaC 2: lanthanum carbide: 12071–15–7 LaCl 3: lanthanum chloride: 10099–58–8 LaCl 3 •3H 2 O: lanthanum chloride trihydrate: 35564–84–2 LaCl 3 •7H 2 O: lanthanum ...
The CuTi 2 structure of the lanthanum, cerium and praseodymium diiodides along with HP-NdI 2 contain 4 4 nets of metal and iodine atoms with short metal-metal bonds (393-386 La-Pr). [10] these compounds should be considered to be two-dimensional metals (two-dimensional in the same way that graphite is). The salt-like dihalides include those of ...
Lanthanum hexaboride (LaB 6) and cerium hexaboride (CeB 6) are used as the coating of some high-current cathodes. Hexaborides show low work function, around 2.5 eV. They are also resistant to poisoning. Cerium boride cathodes show lower evaporation rate at 1700 K than lanthanum boride, but it becomes equal at 1850 K and higher. Cerium boride ...
Lanthanum carbonate – La 2 (CO 3) 3; Lanthanum magnesium – LaMg; Lanthanum manganite – LaMnO 3; Lanthanum mercury – LaHg; Lanthanum silver – LaAg; Lanthanum thallium – LaTl; Lanthanum zinc – LaZn; Lanthanum boride – LaB 6; Lanthanum carbonate – La 2 (CO 3) 3; Lanthanum(III) chloride – LaCl 3; Lanthanum trifluoride – LaF 3 ...