Mossbauer spectroscopy equipment

The great advantage of Mossbauer spectroscopy for catalyst research is that it uses 7-radiation of high penetrating power such that the technique can be applied in situ. An economic advantage is that the technique is relatively inexpensive. The price is about a factor of ten less than equipment for electron microscopy or photoelectron spectroscopy. 

Despite all the information that might be obtained using Mossbauer spectroscopy, some of its limitations naturally discouraged many chemists from using this new technique. Unfamiliarity with the basic principles, the fact that most of the early work was done only on iron and tin, and the lack of commercially available research quality equipment until 1965 were other reasons for the lack of interest. This symposium. The Mossbauer Effect and Its Application in Chemistry, was sponsored by Nuclear Science (formerly Nuclear Science Engineering Corp.), a division of International Chemical Nuclear Corp., with the hope that more chemists would learn how Mossbauer spectroscopy has been and can be used. 

NRVS is related to Mossbauer spectroscopy (see Mossbauer Spectroscopy), but it cannot be easily realized nsing conventional Mossbauer equipment. Practical NRVS experiments target the sample containing the probe nucleus ( Fe, for example) with X-rays generated by a synchrotron radiation facihty. The incident photon energy varies around... 

The samples were characterized by means of X-ray diffraction (XRD) analysis, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), electron diffraction (ED), and Mossbauer spectroscopy. XRD analysis was carried out on a HZG-4A diffractometer by using Ni-filtered Co Ka radiation. IR-spectra were recorded on an AVATAR FTIR-330 spectrometer. TEM/ED examinations were performed with a LEO 906E and a JEOL 4000 EX transmission electron microscopes. The resonance spectra were recorded in air at 298 K and processed by using a commercial SM2201 MSssbauer spectrometer equipped with a 15 mCi Co (Rh) source. 

The preparation chamber, number I in Figs. 1.2 and 1.3, is equipped with two electron beam evaporators and an effusion cell. A four-pocket mini electron beam evaporator serves for deposition of metals from rods and crucibles from each pocket separately, as well as for codeposition of different combinations of the evaporants. A single-pocket e-beam source is used for deposition of the Mossbauer isotope Fe. An effusion cell Is available for evaporation of rare-earth metals. A precise calibration of the deposition rate with a thickness reproducibility of I A is done by a quartz-balance monitor. The deposited structures can be characterized by low-energy electron diffraction (LEED) and Auger electron spectroscopy (AES). In this chamber, the samples can be cooled down to about 90 K and heated up to 2300 K by a multifunctional manipulator. 

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