Evacuated capsule

E)ven though it is evacuated, capsules have been known to explode because the quartz (metal) walls could not contain the internal vapor pressure of the material being grown as single crystal. Care must be exercised not to handle the hot ciy>sule before and after crystal growth. 

The adopted value of T is that reported by Reneshea et al. ( ). This value, 205.7 C or 478.9 K, was obtained by visual observation on four different samples in evacuated capsules. Other values for reported in the literature are 205.3 1.5... 

There is another method that has been sometimes employed in the vapor phase growth of crystals. This method uses an evacuated capsule as shown ... 

Direct reaction of stoichiometric amounts of the elements in evacuated capsules at 1200°C. 

There is another method that has been sometimes employed in the vapor phase growth of eiystals. This method uses an evacuated eapsule as shown in 6.12.4., given on the next page. The eapsule is generally made from quartz, although platinum is sometimes used. Tlie capsule needs to be evacuated to remove any residual gas before heating is started. Otherwise, the internal pressure would build until the eapsule would explode. 

The best-known design of a diaphragm vacuum gauge is a barometer with an aneroid capsule as the measuring system. It contains a hermetically sealed, evacuated, thin-walled diaphragm capsule made of a copper-beryllium alloy. As the pressure drops, the capsule diaphragm expands. 

For the x-ray work, wire samples were prepared by shearing 0.010-inch sheet of the desired uranium-zirconium alloy composition, keeping the width as close to the thickness as possible. A small batch of these wires was then hydrided at 600° C. to the desired hydrogen content along with a small block of the same alloy to bring the sample weight to a feasible value. The hydrided material of each composition was then sealed in an evacuated Vycor capsule and homogenized at 1000° C. 

---