Lindemann glass

For the X-ray scattering observations the samples were powdered and placed in Lindemann glass capillary tubes. The capillaries were held for 8 weeks at 293 K in closed containers in contact either with hexane vapour or with aqueous salt solutions of different relative humidity. At the end of the preparation, the capillary tubes were flame-sealed. X-ray measurements were made at the BM2 bending magnet beam line at the ESRF, Grenoble, France. With incident energy 18 keV, the wave vector range explored was 6x 10 [Pg.44]

A 0.5 mm diameter Lindemann glass capillary of sample I was mounted on the powder diffractometer at station 2.3 at CCLRC Daresbury Laboratory, Synchrotron Radiation Source and room temperature synchrotron X-ray data were collected. The mean wavelength used was 1.2999 A and data were collected from 6 to 80° 20. The diffractometer operated with a Si(lll) monochromator, parallel foils prior to the detector and a scintillation detector. The sample was spun during data collection to minimise preferred orientation and sampling effects. Data were collected on sample II in a similar manner but at a wavelength of 1.3000 A. 

The cylindrical sample is kept as small as possible to minimize the absorption of diffracted radiation. The optimum thickness is jpmP, where p is the sample density. Cylinders are generally kept at 0.5rmm or less diameter. When dilution is necessary, an amorphous substance such as flour is used as the diluent. It is best that the cylindrical sample not be in a container, but in many cases this is not possible. Satisfactory container materials include lithium borate ( Lindemann glass) or various plastics because of their low mass-absorption coefficients the container is a tube with a wall-thickness of about 0.01-mm. 

Lindemann Glass. A lithium beryllium borate glass that is highly transparent to X-rays. It is made from a batch consisting of 10 parts Li2B207,2 parts BeO and 3 parts B2O This glass is difficult to shape and is of low chemical durability. (C. L. Lindemann and F. A. Lindemann. Z. Roentgenkunde, 13,141,1911.) Lindemann-Danielson Test. See... 

---