Mossbauer, Rudolf

The Mossbauer effect, discovered by Rudolf L. Mossbauer in 1957, can in short be described as the recoil-free emission and resonant absorption of gamma radiation by nuclei. In the case of iron, the source consists of Co, which decays with a half-life of 270 days to an excited state of Fe (natural abundance in iron 2%). The latter, in turn, decays rapidly to the first excited state of this isotope. The final decay generates a 14.4 keV photon and a very narrow natural linewidth of the order of nano eV. 

The conclusion of all this is the following. If we place our two atoms in a lattice and do the experiment under conditions where recoil energy of the photon emission and absorption are significantly smaller than the energy of the lattice vibrations, a fraction of the photons emitted by the source nucleus will be absorbed by the nucleus in the absorber. This is the Mossbauer effect, named after Rudolf L. Mossbauer, who discovered it in 1957 and received the Nobel Prize in 1961 [9]. 

Ti ossbauer spectroscopy is the term now used to describe a new ana-lytical technique which has developed using y-ray nuclear resonance fluorescence or the Mossbauer effect. For most of the time since Rudolf Mossbauer s discovery in 1958 it was the physicist who utilized this new tool. Starting approximately in 1962 some chemists realized the potential of this new technique. Since then they have applied Mossbauer spectroscopy to the study of chemical bonding, crystal structure, electron density, ionic states, and magnetic properties as well as other properties. It is now considered a complimentary tool to other accepted spectroscopic techniques such as NMR, NQR, and ESR. 

Rudolf Mossbauer found during work on his PhD thesis in 1953 that, if Ir nuclei are embedded in a crystal lattice, there is a certain probability for recoil-free emission and absorption of y quanta. Later he received the Nobel prize because in the meantime it had been found that recoil-free emission and absorption of y quanta also worked for Fe and this boosted the application of the technique in physics, material science, and chemistry. A very instructive description of these investigations can be found in his Nobel lecture. ... 

Because Miattice is much larger than the nnclear mass M, the recoil energy is negligible and resonance absorption takes place. In terms of quantum mechanics, there is a probability / for a zero-phonon process, where no lattice vibrations are excited. Rudolf Mossbauer showed that the probability / for a zero-phonon process is given by the subsequently named Lamb-Mossbauer factor ... 

It is not. This is more like Max Perutz. He is this big picture in front of me, both as a human being and as a scientist. I see him at least once a year. We are both in the Order pour le Merite of Germany. There are about 70 members, half of them Germans and the other half from other countries. It has a French name Friedrich the Great founded it as a military order at that time the language of communication was French. King Friedrich Wilhelm IV added, under the influence of Alexander von Humboldt, the peace class for science and arts to the Order. It embraces all fields of culture and about one third of its members are scientists. Rudolf Mossbauer became... 

Robert Hofstadter, Rudolf Mossbauer 1904 Lord Rayleigh... 

Mdssbauer, Rudolf (1929-) received the Nobel Prize in Physics in 1961 for the discovery of the Mossbauer effect. 

The Mossbauer effect was discovered in 1958 by Rudolf L. Mossbauer who received the Nobel Prize in physics for its discovery in 1961. Over the past 45 years the Mossbauer effect has developed into a well-established spectroscopic technique which has widely contributed " to coordination chemistry, inorganic and bioinorganic chemistry, and materials science. 

Mossbauer spectroscopy is based on the Mossbauer effect discovered by Rudolf Mdssbauer (Mossbauer 1958a, b). The discovery was honored by the Nobel Prize in 1961. 

The key problem, i.e., how to avoid recoil and Doppler broadening at the same time, has been solved by Rudolf Mossbauer (Mossbauer 1958a) when he discovered that y-ray emitting and absorbing nuclei if embedded in the lattice of a solid give rise to a recoilless line (the so-called Mossbauer line) at the energy Eq. 

Shortly after the discovery of recoilless nuclear resonance emission/absorption on Ir by Rudolf Mossbauer (Mossbauer 1958a) the Mossbauer effect was shown with Fe (Shiffer and Marshall 1959 Pound and Rebka 1959 Hanna et al. 1960 de Pasquali et al. 1960) and... 

Rudolf Mossbauer showed that if the excited nucleus is free, the recoil energy and momentum are taken by the nucleus itself. However, in a solid where the atoms are bound into a crystal lattice, momentum and energy go into lattice vibrations i.e., phonons. Since the entire lattice will absorb the... 

Since the discovery of the Mossbauer effect by Rudolf MSssbauer [1]-[3] in 1958 this nuclear spectroscopic method has found a wide variety of applications in materials science, solid state physics. chemistry, metallurgy, and earth sciences. 

Rudolf Mossbauer, while working on his Ph.D. thesis, carried out experiments of this kind with lr. But surprisingly, on lowering the temperature he found an increase in the absorption effect rather than a decrease. Mossbauer was able to explain this unexpected phenomenon, and was awarded the Nobel Prize in 1961 for the observation and correct interpretation of the recoilless nuclear resonance absorption (fluorescence) which is now known as the Mossbauer Effect and which provided the basis for a powerful technique in solid state research. 

Rudolf Mossbauer discovered the Mossbauer Effect in 1957, while he was working on his doctoral thesis, and received the Nobel Prize for Physics just four years later [3]. The basis of the effect is nuclear resonance between two nuclei of the same isotope. One is in an excited nuclear state and relaxes by emission of a 7 photon, while the other absorbs this photon and is thereby promoted into an excited state (Figure 6.2). 

The examples of chemical applications of Mossbauer spectroscopy discussed in this Tutorial Lecture have mostly been selected from the authors own research work and can, of course, only provide the reader with ideas about the kind of problems that can be solved with this nuclear resonance technique. Since the discovery of recoilless nuclear resonance absorption ( Mossbauer effect ) by the german physicist Rudolf Mossbauer more than fifty years ago, Mossbauer spectroscopy has developed to a poweifril tool in solid state research, making use of more than twenty Mossbauer-active nuclides from the list of more than fourty isotopes for which the Mossbauer effect has been observed [17]. Mossbauer spectroscopy has mostly been employed in conjunction with other physical techniques in order to gain more conclusive information in certain studies, but also in cases where certain problems could not be solved by other techniques. 

The discovery of the resonant absorption of gamma-rays in lr by Rudolf Mossbauer in 1958 was a milestone in nuclear physics because it was formerly assumed that such a phenomenon could never occur due to the large recoil energies involved. The interest for this new finding was nevertheless still limited in the first years, but, a real breakthrough emerged from the fact that many isotopes showed a larger and much more sensitive effect. So, a new technique, called Mossbauer spectroscopy, was bom. The most important feature of this spectroscopic method is the extreme sharpness of the emission line which can easily be... 

The Mossbauer effect, also known as the recoilless nucleus resonance absorption of gamma rays, was first discovered and explained by Rudolf L. Mossbauer in 1957, while he was working on his doctoral thesis at Heidelberg. In the following years, more thorough understanding concerning principles, methods, and applications has been achieved by a myriad of research. 

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