On the impossibility of measuring a galvano-gravitomagnetic effect with current carrying semiconductors in a space-based experiment
In this paper we investigate the feasibility of a recently proposed space-based experiment aimed to detect the effect of the Earth's gravitomagnetic field in space-borne semiconductors carrying radial electric currents and following identical, in principle, circular equatorial orbits along opposite directions. Identical voltages of gravitomagnetic origin would be induced across the orbiting semiconductors, while equal and opposite gravitoelectric larger voltages would be generated. It turns out that the deviations from the proposed idealized orbital configuration due to the unavoidable orbital injection errors would make impossible the measurement of the gravitomagnetic voltage of interest.
Test for relativistic gravitational effects on charged particlesp.
Experimental results are presented which provide the first measurement of the effects of a gravitational field on charged particles, equivalent to the red shift for photons. Two Josephson-effect batteries (Vapprox. =300 ..mu..V) having a vertical separation of 7.2 cm are connected in opposition by superconducting wires. A voltage difference of 2.35 x 10/sup -21/ V is maintained between these batteries by means of the gravitational red shift. The emf around this loop is, however, measured to be less than 1 x 10/sup -22/ V, consistent with the predicted invariance of the gravito-electrochemical potential along the wires.
Refinement of crystal structure parameters using convergent‐beam electron diffraction: the low‐temperature phase of SrTiO3
The method to refine crystal structure parameters (atom positions and Debye–Waller factors) using convergent-beam electron diffraction (CBED), which is applicable to crystal structure analysis of a small specimen area down to a few nm in diameter, is studied. The line profiles of higher-order Laue-zone reflections are recorded using imaging plates. Theoretical intensities are calculated based on the dynamical theory of electron diffraction with the aid of the generalized Bethe approximation to shorten calculation time. The structural parameters are determined by fitting the experimental profiles with the theoretical ones using a nonlinear least-squares method. The present method has been applied to the low-temperature phase of SrTiO3. The structural parameter or the rotation angle of the oxygen octahedron has been determined to be \varphi = 1.12 (4)°, which shows good agreement with that obtained from electron spin resonance experiments.