Beryllium nitride

Beryllium Nitride. BeryUium nitride [1304-54-7], Be N2, is prepared by the reaction of metaUic beryUium and ammonia gas at 1100°C. It is a white crystalline material melting at 2200°C with decomposition. The sublimation rate becomes appreciable in a vacuum at 2000°C. Be2N2 is rapidly oxidized by air at 600°C and like the carbide is hydrolyzed by moisture. The oxide forms on beryllium metal in air at elevated temperatures, but in the absence of oxygen, beryllium reacts with nitrogen to form the nitride. When hot pressing mixtures of beryUium nitride and sUicon nitride, Si N, at 1700°C, beryllium sUicon nitride [12265-44-0], BeSiN2, is obtained. BeSiN2 may have appHcation as a ceramic material. 

There is a reaction between beryllium and nitrogen that starts at about 750°C and is appreciable at 850°C, beryllium nitride being formed". The reaction with oxygen is less sluggish and at 900°C in oxygen oxidation proceeds at about twice the rate of nitride formation. Thus when beryllium is heated in air, beryllium nitride forms only a small proportion of the total scale —about 0-75% after 1 h at 1 000°C. 

Beryllium iodide, 3 663 Beryllium nitrate, 3 664-665 Beryllium nitrate tetrahydrate, 3 664-665 Beryllium nitride, 3 665 Beryllium oxalate, 3 665 Beryllium oxalate trihydrate, 3 665 Beryllium oxide, 3 665-666 5 582 21 491 ceramic insulator, 5 593 energy gap at room temperature,... 

Beryllium does not react with oxygen at ordinary temperatures and normal atmosphere. When heated above 700°C, the metal combines with nitrogen, (in an oxygen-free atmosphere) forming beryllium nitride, BesN2. 

Beryllium nitride is used in nuclear reactors and to produce radioactive carbon-14 isotope for tracer applications. 

Beryllium nitride may be prepared by heating beryllium metal powder with dry nitrogen in an oxygen-free atmosphere above 700°C ... 

At ambient temperatures beryllium is quite resistant to oxidation highly polished surfaces retain the brilliance for years. At 700°C oxidation becomes noticeable in the form of interference films, but is slow enough to permit the working of bare beryllium in air at 780°C. Above 850°C oxidation is rapid to a loosely adherent white oxide. The oxidation rate at 700°C is parabolic but may become linear at this temperature after 24—48 hours of exposure. In the presence of moisture this breakaway oxidation occurs more rapidly and more extensively. Beryllium oxide [1304-56-9], BeO, forms rather than beryllium nitride [1304-54-7], Be,N2, but in the absence of oxygen, nitrogen attacks beryllium above 900°C. 

The methods of choice for beryllium oxide in beryllium metal are inert gas fusion and fast neutron activation. In the inert gas fusion technique, the sample is fused with nickel metal in a graphite cmcible under a stream of helium or argon. Beryllium oxide is reduced, and the evolved carbon monoxide is measured by infrared absorption spectrometry. Beryllium nitride decomposes under the same fusion conditions and may be determined by measurement of the evolved nitrogen. Oxygen may also be determined by activation with 14 MeV neutrons (20). The only significant interferents in the neutron activation technique are fluorine and boron, which are seldom encountered in beryllium metal samples. 

Mercuric acetate, merCury(II) acetate 28 Beryllium nitride... 

Beryllium nitride, alpha (BegN2) Beryl linn oxide (BeO)... 

The isotope used to prepare labelled compounds is obtained by irradiation in a nuclear reactor, of solid targets containing atoms of nitrogen (aluminium or beryllium nitride), by neutrons of low energy, known as thermal neutrons, themselves the product of the controlled atomic fission of The radiocarbon formed is next isolated from the target sample by oxidation to Ba " 003, the variety in which it is delivered to chemists. From C02, it is possible to use a plethora of organic chemical reactions to synthesize different compounds in which the radio-isotope can be introduced to a specific position. 

Be3N2 ALPHA BERYLLIUM NITRIDE 178 CBr2l2[g] DIBROMODIIODOMETHANE (GAS) 219... 

Beryllium nitride Be3N, 1304-64-7 66.060 gray refrac cry cub 2200 2.71 reac acid, alk... 

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