METHOD FOR DETERMINING CONCENTRATION OF CHARGE CARRIERS IN DEGENERATED SEMICONDUCTORS Russian patent published in 1994 - IPC

FIELD: nondestructive tests. SUBSTANCE: specimen is cooled down to helium temperatures and exposed to varying stationary magnetic field B and to alternating magnetic field with amplitude h<<B simultaneously. Then specimen is exposed to monochromatic coherent radiation directed perpendicular to stationary magnetic field B and having quantum energy lower than semiconductor forbidden energy band and polarized so that vector of electric field strength is perpendicular to stationary magnetic field B. Intensity 1 of beam passed through specimen or reflected from it is recorded. Concentration of charge carriers is determined according to adjacent maxima of curve showing second derivative d²1_o/B² as function of B using equation , where K = 0,1,2,3 ...; I is electron charge; h is Dirac constant: N is maximum number (Landau level number): B_N and B_N+1 are flux densities of stationary magnetic field corresponding to two adjacent maxima N and N+1. EFFECT: improved accuracy and facilitated location of flaws in nondestructive tests. 3 dwg