Fig. 7From: Constraining the magnetic properties of ultrafine- and fine-grained biogenic magnetiteCurves of real and imaginary components, χ′ and χ″, of the AC susceptibility versus temperature. Samples were measured at frequencies of 1 Hz, 5 Hz, 10 Hz, 50 Hz, 100 Hz, 200 Hz, 500 Hz, 1000 Hz in a peak AC field of 0.4 mTBack to article page