  First-order reversal curves (FORC) measurements are broadly used for
characterization of complex magnetic nanostructures, but a robust framework for
quantitative analysis of the FORC data is still obscure despite numerous
studies over decades. In this paper, we first establish a framework for
extracting quantitative parameters from the FORC measurements conducted on
samples including a single type of magnetic nanostructures to interpret their
magnetic properties. We then generalize our framework for quantitative
characterization of the samples including multiple types of magnetic
nanostructures to determine the most reliable and reproducible parameter for
detailed analysis of the samples. Our approach provides an insightful path for
a more accurate quantitative description of complex magnetic nanostructures
including various different magnetic subcomponents and/or magnetic phases.
