“Some of these are force microscope images of the magnetic particles which shows their shape and their magnetic attraction (red) and repulsion (blue).
My colleague (Jonathan) helped to produce these, as they use a programme called ‘R’ to plot all the data. I tended to put them with an SEM image (the black and white ones) so you could see the patterns better in the figures.”
The magnetic chessboard patterns are all mainly in this paper.
My thesis (which should be free and have the other references in too).
And there are links to them all on my ResearchGate.”