No abstract

No abstract

Using a Laboratory XAFS(X-ray absorption fine structure) spectrometer, the local structure of aluminium in an aluminosilicate with a Si/Al atomic ratio of 1/3 was studied. From the XAFS data, the average Al-O interatomic distance and coordination number of aluminium atoms were estimated. In addition, the assignment of the XANES(X-ray absorption nearedge structure) spectra for aluminium was discussed based on the 27Al MAS NMR spectra of the corresponding samples.

A new laboratory x‐ray absorption fine structure (XAFS) spectrometer specially designed for measurements of the absorption spectra of light elements is presented. The spectrometer consists of a newly developed rotating‐anode x‐ray source of portable size, a power supply of low‐voltage and high‐current type, a vacuum x‐ray path, a Johann‐type curved monochromator, a cell unit for high‐temperature measurements, and a solid‐state detector (SSD) system with a single‐channel analyser. The SSD system can eliminate x‐rays of other orders to give x‐ray absorption data containing no noise due to high frequencies. A current control method is employed to suppress characteristic x‐rays emitted from filament and target materials. The performance of the spectrometer was evaluated by x‐ray absorption measurements on a copper foil at the Cu K‐edge at room temperature and on powdered gibbsite and aluminosilicates at the Al K‐edge. The results showed that the spectrometer is capable of obtaining good quality XAFS and x‐ray absorption near‐edge structure (XANES) spectra at Al and Cu K‐edges within about 2 h. Thus, both XAFS and XANES studies will be possible with the spectrometer for a wide range of elements from sodium to lanthanides by use of suitable monochromator crystals.

No abstract