Single crystals, of transition metal

Single crystals of transition-metal hydrides cannot be grown from the melt by the usual techniques because the hydrides dissociate at temperatures well below their melting points. The method used here is one of compound formation from saturated elemental melts. It is a modification of the technique used by Harman ct al.3 and Stambaugh et al.4 for growing crystals of III-V semiconducting compounds. 

On single crystals of transition metal carbides it has been shown for hexagonal WC and also for fee NbCi that the microhardness is dependent of orientation. ... 

Large single crystals of transition metal carbides can... 

In the electron diffraction case, the greatest chaises in the relative intensities of the scattering by single crystals of transition metals should be observed for the first reflections. 

Thus far we have been concerned almost exclusively with low index surfaces of single crystals of pure metals, for good reason. In the older work on metal powders and films, their polycrystalline nature forbade the drawing of conclusions about surface geometry, and their doubtful cleanliness was a continual worry. Only the work on FEM and FIM produced results of comparable importance, although these techniques are now rarely used. There have however been a number of studies of stepped surfaces. The behaviour of chemisorbed hydrogen on Ni(997), which is a stepped version of Ni(l 11), is dominated by the plane areas, but the order-disorder transition from the (2 x 2)2H phase to the randomly located lattice gas was raised by about 40 K by the presence of the steps, which stabilise the ordered structure. 

A series of Be-Pt intermetallic compounds arc prepared during the electrodeposition of Be on Pt from a solution of BeCl2 in an equimol NaCl-KCl mixture at 710°C. X-Ray diffraction of the electrode surface shows the presence of BePt, BcjPt. Electrolytic methods are also used to extract single crystals of Be,V from alloys prepared by arc melting Be and the transition metal in the proportion 15 1. 

In these cases, one is limited to the growth of single crystals of the transition metals since it is those metals which form volatile carbonyl compounds. The alkali metals, alkaline earth metals and certain of those elements which are allotropic in nature are not at aH suited for this type of crystal growth. 

When a substance is transparent to visible light, such as single crystals of simple inorganic solids which do not contain transition metal ions, or some glasses, another significant component in the thermal conductivity is the transmission of photons in the infra-red region, which becomes more important with... 

This j taper describes equipment, procedures and results for investigation of transition metal surface reactivity. Specifically, the surface reactivity of copper single crystals was examined under conditions relevant to the electrochemistry and corrosion of copper. 

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