Dislocation loops consisting of long and straight segments of 60? and screw parts were introduced in p-type Si by deformation under a high stress at a relatively low temperature. Electronic states associated with such dislocations were investigated by means of electric-dipole spin resonance, with... (Read more)

The observation of optically detected magnetic resonance (ODMR) signals directly correlated with dislocations in silicon is reported. The ODMR signals are identified as resonances from free electrons, dangling bonds, and quasifree holes bound to a one-dimensional potential in straight dislocations.... (Read more)

The velocity v of dislocation half-loops introduced into swirl-free floating-zone grown undoped silicon has been measured at 420°C in the resolved shear stress range 30 <τ<300 MPa. Clearly impurity atoms interact with dislocations in this material. Using the starting value of v we found the two types of 60° dislocations, which are distinguished by the sequence of their partials, to have different velocities. Furtheron the velocity depends not only on τ, but also on the elastic strain of the lattice. In the second part the papers review EPR spectroscopy of plastically deformed silicon and collects new results on the activity of dislocations in this material as trapping / recombination centers (decay of photo-EPR, photoluminescence, EBIC microscopy and photoplastic effect). (Read more)

We investigated the properties of the dislocation sEPR spectra in Si in the temperature interval from 1.3 to 150ºK. At helium temperatures we observed anomalies in the behavior of the dispersion signals χ' under conditions of adiabatic rapid passage (APR) through resonance. It is shown that the spectrum of the D centers has a hyperfine (hf) structure, with a line width ∆H_i ～0.2－0.3 Oe (the distance between neighboring hf lines is of the order of their width). It is established that under ARP conditions excitations are transferred between the hf lines as a result of spin-spin interactions with a characteristic time τ₃, equal to 3－10 sec in the range 1.3－4.2ºK and weakly dependent on the temperature and on the microwave power. We measured the dependence of the integrated intensity of the absorption signals χ'' on the temperature in the 20－150ºK range. A strong deviation from the Curie low was observed at T=40－50ºK. The temperature dependence of the quantity τ₁τ₂ was measured in the same temperature range, under the assumption that the hf lines have a Lorentz shape. An anomaly at T=40－50ºK was observed also on the plot of τ₁τ₂=f(1/T). It is concluded that a magnetic phase transition takes place in the D-center system at 40－50ºK, and consequently the dislocations in Si can be regarded as models of one-demensional chain of spins with exchange interactions.

Bei 800°C verformte Silizium-Kristalle zeigen ein Elektronenspinresonanz-Signal, dessen Intensität mit der Versetzungsdichte zunimmt. Wir vermuten, daβ dieses Signal von ungepaarten Elektronen im Kern von Versetzungen stammt. Durch die Verformung wird die Bildung von Atomgruppen in... (Read more)