Interface structure of Fe/Ag multilayers prepared by pulsed laser deposition

Abstract

Fe/Ag multilayers with single layer thicknesses in the nanometer range have been deposited on Si͑100͒ using pulsed laser deposition. Conversion electron Mössbauer spectroscopy in conjunction with Rutherford backscattering spectrometry and x-ray reflectivity have been used for the evaluation of the interface structure of these multilayers. In the Fe-Ag system, with a large positive heat of mixing, a solid solution of bcc Fe͑Ag͒ has been found by placing an enriched 57 Fe marker layer at different distances to the multilayer interfaces. The interface structure mainly depends on dynamic effects during the deposition processes. From the analyses, we have obtained an asymmetric intermixing at lower and upper interfaces of the individual Fe layers: the intermixing of Fe into Ag is lower than that of Ag into Fe. The studies of the interface structure were performed by varying parameters such as the thickness of the elemental layers and the target-to-substrate distance during the deposition process.

Dynamics of ions produced by laser ablation of several metals at 193 nm

“…It is generally accepted that the special features or improved performance relate to their different microstructure when compared to systems produced using conventional techniques. [1][2][3][4] The high kinetic energy of species arriving to the substrate is the most widely reported reason for these differences, but their presence can also lead to undesired processes such as resputtering of deposited species, [4][5][6][7] mixing or alloying at the interface, 8 or subsurface implantation. 4,6,7 The complete origin of many of these processes is not yet well understood in part due to the lack of detailed information on the actual kinetic energy of the species reaching the substrate in a broad laser fluence range, since average or mean values are typically reported rather than velocity distributions.…”

Imaging self-sputtering and backscattering from the substrate during pulsed laser deposition of gold

“…1,2 However, much less attention has been paid to the production of metals despite early attempts to synthesize them in the 1970s. 3 More recently, the interest in complex thin film metal nanostructures such as metal-dielectric or metal multilayers, 4,5 as well as metal nanoparticles, [6][7][8] has triggered new efforts to use PLD for metal deposition. These metal structures are characterized by the localization and enhancement of the electric and magnetic fields, leading to effects such as giant magnetoresistance, 9 enhanced nonlinear optical properties, 8 or enhanced Raman response, 10 among others.…”

“…[11][12][13][14] Both characteristics are expected to have a strong influence on the features of the metal structures produced. 6,15 In addition, the presence of highly energetic species may induce undesired processes such as selfsputtering, also termed resputtering, of a fraction of the material that is being deposited 14,[16][17][18][19] or an increase of surface roughness, 4 among others. Finally, both self-sputtering and backscattering of a fraction of the incident species may have a significant effect on the morphology of the nanoparticles due to their nanometric dimensions.…”

Quantification of self-sputtering and implantation during pulsed laser deposition of gold

“…However, the presence of species having high kinetic energies is a concern due to effects that can be undesired, such as resputtering or self-sputtering of the deposited species, 3,8 mixing or alloying at the interface, 1,2 subsurface implantation 2,3 or even defect formation. It is well known that high kinetic energy species bombarding a surface can affect the deposition process.…”