Engineering strain, densification, order parameter and magnetic properties of FePt thin films by dense electronic excitations

作者：Gupta Rekha; Sehdev Neeru; Asokan K; Kanjilal D; Annapoorni S^*

来源：Journal of Applied Physics, 2014, 116(8): 083902.

DOI：10.1063/1.4893709

FePt films prepared by DC sputtering on Si %26lt; 100 %26gt; substrates when annealed at 600 degrees C for 1 h exhibited a structurally ordered and magnetically hard L1(0) phase. These FePt films were exposed to dense electronic excitations by using 100MeV oxygen ions as a function of increasing fluences. Such excitations induce pressure and result in the enhancement of order parameter by increasing strain on the FePt films. Apart from this, the surface morphological images from field emission scanning electron microscopy reveal a densification of the films consequent to irradiation and are correlated with the details obtained from Rutherford back scattering analysis. The variation in the values of coercivity correlates well with the change in volume percentage of face centered tetragonal and face centered cubic phase. A coercivity of 14.7 kOe with order parameter 0.92 is achieved at a fluence of 5 X 10(12) ions/cm(2). The theoretical simulation of the demagnetization curve shows a strong correlation of coercivity and order parameter between the experimentally obtained values with that of simulation. The effect of irradiation induced strain, the structural ordering and coercivity of FePt films as a function of fluences have been discussed.

• 出版日期2014-8-28