Sample Preparation

3mm diameter samples were punched from a computer hard disk and mounted with conductive tape onto a sample stub. Rapid sample introduction into the analysis chamber of up to 10 samples is possible by utilizing the optional carousel system of the AMICUS allowing high throughput of samples. Photoelectron spectra were recorded with the  Mg Kα source. Depth profiling was performed using the integral Ar⁺ ion gun coupled with automatic sample rotation to ensure both rapid etch rates and excellent interface resolution.

Figure 2: X-Ray photoelectron survey scans as a function of depth from the

Hard Disk Media - Depth Profile

The initial investigation of the hard disk samples involved recording survey scans as a function of sputter time, to determine the elemental composition of the revealed surface material after each sputter. Survey scans as a function of depth from the "as introduced" surface are shown in Figure 2. The identification of each layer is highlighted by the accompanying schematic cross section of the hard disk in Figure 1.

From these survey scans, the composition of each layer could be determined and a complete concentration profile calculated through the hard.disk. Figure 3 shows the concentration of the component hard disk layers as a function of depth from the surface. This figure demonstrates the well-defined interface boundaries between each layer, with no obvious degradation in the interface resolution as a function of depth. Also noted is the persistence of carbon contamination, through the magnetic media layers.

Figure 3: Elemental concentration profile of a computer hard disk.