Schematic diagram of the TEDDI system; the incident white beam from the synchrotron is collimated to a cross-sectional area of approximately . The beam falls on the ferrite sample which is scanned in two dimensions. A diffracted beam is selected at a chosen angle by means of a collimator placed in front of an energy sensitive detector system. This collects and stores each energy-dispersed diffraction pattern. The gauge volume is defined by the intersection of this collimated beam with the incident beam.
(Color online) TEDDI scan in the direction through the body of the sample. The diffraction patterns are separated by ; preferred orientation effects are clearly visible and indicated by enclosing circles.
(Color) The cross section (corresponding to that shown in Fig. 1) shows the refined lattice parameter output from the energy dispersive data. There are clearly variations at the 1% level with markedly lower density regions (red) at the two surface extremities owing to zinc loss during processing.
(Color online) (a) The REBIC bond pad arrangement on the ferrite material and the position of two of the probes. One of the probes is earthed; the other measures the small currents induced by the electron beam. (b) Scanning electron microscopy image of the ferrite material. The porous nature of the surface can be seen clearly with the voids having an average dimension of less than . (c) REBIC image of a scan between two bond pads. The lack of any sharp feature shows that the known defects and grain boundaries are not electrically active. (d) REBIC current collected between two electrode pads and indicating a steady, rather than discontinuous, change.
(Color online) Local resistivity as a function of distance (collected at two different locations) on a cross section from a ferrite torroid. There is no direct spatial correlation between the two scans but the variation in resistance is of the order of over an average distance of .
(Color online) Density of states for the ; the spin-up and spin-down states are identified. The top of the spin-up state (marked) is very close to the Fermi surface and is responsible for the majority of the conductivity in the material. The bands widen and decrease as a function of decreasing lattice parameter, caused by the method of manufacture.
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