Magnetic texture in amorphous Fe40Ni35Si10B15 alloy irradiated with swift heavy ions

The influence of swift-heavy-ion irradiation on the orientation of the hype rfine field in amorphous Fe40Ni35Si10B15 alloy is studied by Mossbauer spec troscopy. The change of the magnetic texture induced by 6 GeV Ph-ion irradi ation is studied as a function of ion energy and the linear rate of electro nic energy deposition for ion fluences ranging from 1 x 10(11) to 2.4 x 10( 13) ions cm(-2) The Mossbauer measurements revealed that in a substantial v olume fraction of the irradiated samples the spins changed their orientatio n from the in-plane orientation to the perpendicular one. This effect was a ttributed to the formation of cylinders of 'modified' amorphous structure a long the ion path which may induce a stress as a result of which a substant ial fraction of spins are aligned along the beam direction, i.e. perpendicu lar to the plane of the sample.