Relaxation in metal

C.J. Rank. Evaluation of difftision and relaxation in metallic glasses after short-term annealing in a mirror furnace. PhD thesis, Stuttgart University, 1992. In German. 

Optical properties of electronic and magnetic systems were discussed in talks by R. Hicken (Electron relaxation in metals by femtosecond ellipsometry) and R. Pisarev (Nonlinear optical spectroscopy). 

In the phenomena of reversible and irreversible relaxation in metallic glasses, the low-energy excitations connected with the rearrangement of atomic configurations including the tunneling states play an essential role. The description of low-energy excitations and diffusion mechanisms in polyclusters is contained in Sects. 6.6 and 6.7. 

For more details on relaxation in metals, we refer you to the books by Abragam and Slichter listed in the general section of Appendix A as well as that by Winter (1971). For relaxation by spin diffusion to paramagnetic impurities, we refer you to the article by Noack (1971) and references contained therein. 

There is a relationship between l/Tj and the Knight shift in metals that is very sensitive to electron correlation and exchange. To explain this and to derive its implications for expanded alkali metals, we digress briefly to summarize some results of the general theory of nuclear spin relaxation in metals. For noninteracting electrons, the theory of nearly free electrons gives an explicit expression for the integral in Eq. (3.10)... 

ESR can detect unpaired electrons. Therefore, the measurement has been often used for the studies of radicals. It is also useful to study metallic or semiconducting materials since unpaired electrons play an important role in electric conduction. The information from ESR measurements is the spin susceptibility, the spin relaxation time and other electronic states of a sample. It has been well known that the spin susceptibility of the conduction electrons in metallic or semimetallic samples does not depend on temperature (so called Pauli susceptibility), while that of the localised electrons is dependent on temperature as described by Curie law. 

Carotenoids incorporated in metal-substituted MCM-41 represent systems that contain a rapidly relaxing metal ion and a slowly relaxing organic radical. For distance determination, the effect of a rapidly relaxing framework Ti3+ ion on spin-lattice relaxation time,and phase memory time, Tu, of a slowly relaxing carotenoid radical was measured as a function of temperature in both siliceous and Ti-substituted MCM-41. It was found that the TM and 7) are shorter for carotenoids embedded in Ti-MCM-41 than those in siliceous MCM-41. 

---