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A series of 20 and 100 nm Fe53Pt47 thin films sputter-deposited onto Si substrates have been thermally annealed using a pulsed thermal plasma arc lamp. A series of one, three or five pulses were applied to the thin films with widths of either 50 or 100 ms. The microstructure and magnetic properties of these annealed Fe53Pt47 films are discussed according to the various annealing conditions and A1 to L10 phase transformation. Upon pulse annealing, the average in-plane grain size of 15 nm (nearly equivalent for both film thicknesses) was observed to increase to values near 20 nm. In general, increasing the pulse width or number of pulses increased the L10 order parameter, tetragonality of the c/a ratio and coercivity of the specimen. The exception to this trend was for five pulses at 100 ms for both film thicknesses, which indicated a reduction of the order parameter and coercivity. This reduction is believed to be a result of the interdiffusion of Fe and Pt into the Si substrate and the formation of iron oxide clusters in the grain boundaries characterized by atom probe tomography.

Sputter-deposited, equiatomic PtMn thin films have application in giant magnetoresistive spin valves, tunneling magnetoresistive spin valves, and magnetic random access memory. However, the as-deposited films are found to be a disordered A1 phase in a paramagnetic state rather than an antiferromagnetic phase with L10 structure, which is needed for device operation. Therefore, a postannealing step is required to induce the phase transformation from the asdeposited A1 face-centered-cubic phase to the antiferromagnetic L10 phase. The A1 to L10 metastable transformation was studied by x-ray diffraction and differential-scanning calorimetry. An exothermic transformation enthalpy of −12.1 kJ/mol of atoms was determined. The transformation kinetics were simulated using the Johnson-Mehl-Avrami analysis.

The effect of pulsed-thermal-processing with high-density plasma arc heating is discussed for 20 nm thick nanocrystalline FePt thin films. The dependence of the A1→L10 phase transformation on pulsed time and radiant energy of the pulse is quantified through x-ray diffraction and alternating gradient magnetometry. For 100 ms and 250 ms pulse widths, the phase transformation was observed. Higher radiant energy densities resulted in a larger measured coercivity associated with the L10 phase.

The nanotribological performance of Ti–B–N protective coatings, 500 nm thick, have been studied in the range of 0–38.5 at.% N. A correlation was established amongst the chemical state, structure, mechanical properties, and nanowear resistance as a function of atomic percent nitrogen. The mechanical properties, elastic modulus and hardness, of the films were tested using a Hysitron Triboscope nanomechanical test instrument. The nanotribological performance of the films was evaluated using a Nanoindenter II with scratch capability. Single and reciprocating nanowear scratches, 10 μm in length, were performed at normal loads ranging from 50 to 750 μN. An atomic force microscope (AFM) was utilized to characterize the nanowear tracks with respect to depth and amount of plowing of material. The AFM images revealed that the reciprocating nanowear test caused grooving of the films with little to no material removal. Chemical and structural information was obtained by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction. Increasing N content correlated with increasing number of B–N bonds, structural disorder, and decreasing hardness, modulus, and wear resistance.

Thin films (500 nm) of Ti–B–N have been produced by d.c. magnetron sputtering from a TiB2 target in various Ar+N2 gas mixtures. The atomic concentration of nitrogen in the films varies between 0 and 38 at.%. The ratio of boron to titanium in the films is fixed by the relative concentration of these two elements in the TiB2 sputtering target. Bonds of B–N, B–Ti, Ti–N and Ti–B are observed in the B 1s and the Ti 2p spectra. The change of shape observed in the N 1s spectra led to the conclusion that at low nitrogen concentration the nitrogen atoms are preferentially bonded with titanium atoms, in good agreement with thermodynamical data. By using quantitative information from the B 1s, Ti 2p and N 1s curve fittings, the formation of a film containing three separate phases (TiN, BN and TiB2) is discussed. Copyright © 2000 John Wiley & Sons, Ltd.

Thin films of FeTaN have been investigated as potential head materials for several years. However, little information related to its chemical characteristics can be found in the literature, therefore polycrystalline and epitaxial FeTaN films were synthesized by d.c. reactive magnetron sputtering. Follow-up annealing was performed on some of the thin films under vacuum conditions. The chemical compositions and elemental chemical states of both kinds of thin films were investigated by x-ray photoelectron spectroscopy. It is shown that the nitrogen content in the films can be changed and easily controlled by varying the nitrogen gas flow rates during the deposition process. There are no large chemical shifts in the binding energies of Ta 4f, Fe 2p and N Is between polycrystalline and epitaxial films. No chemical compounds among Fe, Ta and N were formed in as-deposited or even in vacuum-annealed thin films. However, a chemical shift of Ta 4f from its atomic state was found. In addition, relatively large contents of carbon and oxygen inside the films were noticed. The existing chemical states, sources and possible effects of nitrogen, carbon and oxygen on the magnetic properties were studied and discussed.

Further insight into processing-structure-property relationships have been carried out for existing and candidate carbon-based protective overcoats used in the magnetic recording industry. Specifically, 5 nm thick amorphous diamond-like carbon (a:C) and nitrogenated diamond-like carbon (a:CNx) overcoats were deposited by low deposition rate sputtering onto a thin film disk consisting of either CoCrPt/CrV/NiP/AlMg or CoCrPt/CrV/glass. The wear durability and frictional behavior of these hard disks were ascertained using a recently developed depth sensing reciprocating nanoscratch test. It was determined that the CN0.14/CoCrPt/CrV/glass disk exhibited the most wear resistance, least amount of plastic deformation, and lowest kinetic friction coefficient after the last wear event. Core level x-ray photoelectron spectroscopy (XPS) results of sputter cleaned overcoats indicated that nitrogen up to 14 at. % incorporated into the amorphous network resulted in these improvements near the overcoat/magnetic layer in...

Pulse thermal processing (PTP) has the capability of processing thin-films and nanoparticles over broad areas utilizing high-density infrared plasma arc lamp technology. Heating rates reaching 600,000°C/s, which is orders of magnitude larger than current state-of-the-art rapid thermal annealing systems, are possible that allow controlled diffusion on the nanoscale. The ability to control heating at these levels permits processing thin-films and nanoparticles on temperature-sensitive substrates such as polymers. The PTP technique has been used to crystallize sputtered amorphous silicon thin-films on sapphire substrates.

Ultra-thin nitrogenated carbon overcoats have attractive tribological properties that make them favourable for protective coatings for rigid magnetic disks. In this study the influence of the overcoat nitrogen content and thickness on the tribological performance, assessed by nanowear tests, was evaluated. The nitrogenated carbon overcoats, with thicknesses ranging from 5 to 10 nm, were deposited on 15 nm thick layers of CoCrPt media.