DETERMINATION OF THE DEPTH OF FORMATION OF MAGNETOOPTICAL EFFECTS IN CONI FILMS

The optical constants of CoNi films with magnetic properties that are nonuniform across their thickness are determined in reflected light by two methods, viz., optical and magnetooptical measurements. The value s of the parameters L = lambda/4 pi k and Z(0)= lambda/8n, one of whic h (specifically, the one which has the smaller value at a given value of lambda) determines the depth of formation of reflective magnetoopti cal effects (l(mo)) according to the current theories, are calculated on the basis of the values obtained for the optical constants n and k of the films (lambda is the wavelength of the light used, and n and k are the refractive index and the absorption coefficient of the magnet) . It is established for the CoNi films investigated that I,, is determ ined by L and varies from about 200 to 300 Angstrom in the range 0.33 mu m less than or equal to lambda less than or equal to 0.83 mu m. In CoNi films, which are inhomogeneous across their thickness and are cha racterized by significant variation of the magnetic properties over di stances similar to l(mo), variation of the form of the magnetization c urves determined by measuring the equatorial Kerr effect is observed a s lambda increases. (C) 1998 American Institute of Physics. [S1063-784 2(98)01302-6].