Fig. 4

IRM/SIRM acquisition curves. a Plot of IRM acquisition and backfield demagnetization curves (inset) for four representative samples, b, c linear acquisition plot (LAP) and gradient acquisition plot (GAP) for two representative samples
IRM/SIRM acquisition curves. a Plot of IRM acquisition and backfield demagnetization curves (inset) for four representative samples, b, c linear acquisition plot (LAP) and gradient acquisition plot (GAP) for two representative samples