The data is organized into the relevant section of the paper: - Sample Characterization - Spin-Wave Resonance - Simulations In the Sample Characterization section: - Included in the Sample Characterization section in the calculation of the exchange stiffness in an excel spreadsheet. Due to a copying error of the results for the value of T_C, the calculated value of A_FM taken forward for the value of A' is incorrect. This discrepancy is very small and has no influence on the results of the experiment and it was not deemed neccesary to re-perform the analysis. - The initial conditions used for the T_C fit were (1800, 652, 0.5). The fit is seen to depend on the initial conditions but again this has little influence on the extracted values and the conclusions drawn from the analysis and so it is deemed unnecessary to reperform the analysis. In the Spin-Wave Resonance section: - The data in this area is organized into material, FeRh and Py. - Both materials have their data organized by the voltage at which the measurements were taken. These are then mapped to a measured temperature and effective temperature for FeRh. The FeRh measurements are also further split into measurements taken when heating and when cooling. Not all measurements in FeRh were deemed to have SWR peaks that are distinguishable from the background and are therefore not included. - For the quantities derived from the behaviour of the central FMR peak, i.e. the spectroscopic splitting factor, g, the measurements are performed in the manner described in chapter 5 of J. R. Massey's thesis (http://etheses.whiterose.ac.uk/24877/).