TY - CHAP

T1 - Analysis of Strong-Field Hysteresis in High Coercivity Magnetic Minerals

AU - Kosterov, A.

AU - Sergienko, E. S.

AU - Iosifidi, A. G.

AU - Kharitonskii, P. V.

AU - Yanson, S. Yu

N1 - Publisher Copyright: © 2020, Springer Nature Switzerland AG.

PY - 2020

Y1 - 2020

N2 - To evaluate the effect of undersaturation of magnetic hysteresis loops measured in moderate (<2 T) fields in magnetically hard minerals such as goethite or hematite, we measured room temperature hysteresis loops in a 7 T field and DC backfield demagnetization curves in fields up to 3 T using an MPMS 3 instrument. Sediments from different regions of the East European platform, mostly of Carboniferous age were used for this study. Similar experiments were also carried out for a small collection of archaeological ceramics (bricks) apparently containing a High Coercivity Low unblocking Temperature (HCLT) magnetic phase (ε-Fe2O3?). Hysteresis measurements were complemented by thermomagnetic analysis at low and high temperatures, microscopic observations, and X-ray diffraction studies. High-field magnetic hysteresis loops alone appear insufficient to definitively discriminate goethite from hematite, though there is, expectedly, a tendency that increasing goethite content leads to magnetic hardening, with coercive force reaching 1 T and coercivity of remanence 1.7 T. At the same time, ε-Fe2O3 can seemingly be distinguished from either hematite or goethite due to its high saturation magnetization. However, combining hysteresis measurements with low- and high-temperature thermomagnetic analysis provides a much better insight into the magnetic mineralogy of samples. Still, acquiring the reference data on well characterized hematite, goethite, and ε-Fe2O3 samples is highly desirable.

AB - To evaluate the effect of undersaturation of magnetic hysteresis loops measured in moderate (<2 T) fields in magnetically hard minerals such as goethite or hematite, we measured room temperature hysteresis loops in a 7 T field and DC backfield demagnetization curves in fields up to 3 T using an MPMS 3 instrument. Sediments from different regions of the East European platform, mostly of Carboniferous age were used for this study. Similar experiments were also carried out for a small collection of archaeological ceramics (bricks) apparently containing a High Coercivity Low unblocking Temperature (HCLT) magnetic phase (ε-Fe2O3?). Hysteresis measurements were complemented by thermomagnetic analysis at low and high temperatures, microscopic observations, and X-ray diffraction studies. High-field magnetic hysteresis loops alone appear insufficient to definitively discriminate goethite from hematite, though there is, expectedly, a tendency that increasing goethite content leads to magnetic hardening, with coercive force reaching 1 T and coercivity of remanence 1.7 T. At the same time, ε-Fe2O3 can seemingly be distinguished from either hematite or goethite due to its high saturation magnetization. However, combining hysteresis measurements with low- and high-temperature thermomagnetic analysis provides a much better insight into the magnetic mineralogy of samples. Still, acquiring the reference data on well characterized hematite, goethite, and ε-Fe2O3 samples is highly desirable.

KW - Day-Dunlop plot

KW - Goethite

KW - HCLT phase

KW - Hematite

KW - Magnetic hysteresis

UR - http://www.scopus.com/inward/record.url?scp=85088224221&partnerID=8YFLogxK

U2 - 10.1007/978-3-030-21788-4_10

DO - 10.1007/978-3-030-21788-4_10

M3 - Chapter

AN - SCOPUS:85088224221

SN - 978-3-030-21787-7

T3 - Springer Proceedings in Earth and Environmental Sciences

SP - 127

EP - 142

BT - Problems of Geocosmos–2018

A2 - Yanovskaya, Tatiana

A2 - Kosterov, Andrei

A2 - Bobrov, Nikita

A2 - Divin, Andrey

A2 - Saraev, Alexander

A2 - Zolotova, Nadezhda

PB - Springer Nature

CY - Cham

ER -