Magnetic and Structural Comparisons of Commercial Metal Evaporated Tapes

Abstract

Measurements of the structural, magnetic, and recording properties of several commercial metal evaporated (ME) tapes are presented. Special attention is paid to the effect of multiple layers, with different easy-axis directions, pn these properties. We find evidence that the different layers in ME tape are magnetically independent from one another.

Interaction in double layered ME tapes

“…5, which confirms the same trend as was found in Ref. [1]; the oxygen depth profile reveals two distinctive peaks which can be contributed to the different layers. Also the width of these peaks correlates with the chosen oxygen flow of the individual layers.…”

“…From the comparison of the SEM cross section and the Auger depth profiles with those from Ref. [1] it becomes clear that our experimental double layers resemble commercially available tapes. Considering the oxygen interlayer it seems not likely that exchange interaction is present between the layers.…”

“…Commercially produced double layered metal evaporated (ME) tapes (e.g. TDK) have better recording characteristics over a wider frequency range and less media noise compared to single layer tapes [1]. The reason for better recording performance might be a decrease in intrinsic domain width in the double layer compared to a single layer of the same thickness.…”

On the vectorial calibration of a vibrating sample magnetometer for thin film measurements

“…One of the errors resulting from these invalid assumptions is an undesired contribution to the signal of a magnetic moment perpendicular to the measuring direction. This is often considered as an error, sometimes referred to as 'cross talk' [1], which is getting increasingly important when the sample size approaches the sample-coil distance, especially when angle dependent measurements are performed. This cross talk problem leads to errors in the magnetisation vector of up to 15% in magnitude and 8°in angle in a configuration where the size of the square sample is half the coil distance.…”

“…Richter [2] introduces a phenomenological correction for the cross talk based on the mean values of magnitude and orientation of the magnetisation, which is a good approximation if the deviations are small. Other methods minimise the effect of the invalid assumptions by adjusting the design of the detection system; Bernards [1] uses an extra set of 4 coils in addition to an 8-coil set-up, Samwel et al [3] avoid the rotation of the sample in respect to the coils and take the different sensitivities for different components into account.…”