Sources of experimental errors in the observation of nanoscale magnetism
  It has been recently reported that some non-magnetic materials in bulk state, exhibit magnetic behavior at the nanscale due to surface and size effects. The experimental observation of these effects is based on the measurement of very small magnetic signals. Thus, some spurious effects that are not critical for bulk materials with large magnetic signals may become important when measuring small signals (typically below 0.0001 emu). Here, we summarize some sources of these small magnetic signals that should be considered when studying this new nanomagnetism 
M. A. Garcia, E. Fernandez Pinel, J de la Venta, A. Quesada, V.   Bouzas, J. F. Fernandez, J. J. Romero, M. S. Martin Gonzal...