Dependence of nonlinear properties of Bi2Sr2CaCu2O8 crystals on the orientation of external magnetic field

Experimental dependences of the spectrum of nonlinear high-temperature supe rconductor responses to an external ac magnetic field have been studied in relation to a sample orientation with respect to ac and de external magneti c fields. In contrast to the case of ceramics, even harmonics can be made t o vanish in a single-crystal HTS at nonzero parallel field component by cha nging the perpendicular component of the de magnetic field. The HL field ne cessary for this effect to occur is a linear function of applied H-parallel to, with the dependence of the proportionality factor on the sample rotati on angle in quantitative agreement with the theoretical model proposed.