z
Octahedral coordination
M
y
z
x
M
x
Tetrahedral coordination
y
Crystal field in an octahedral and tetrahedral environment
octahedral
tetrahedral
S. Blundell, Magnetism in condensed matter, oxford university press
180° wall
90° wall
Magnetic domains as seen by Kerr microscopy
grain
Magnetic
domains
http://en.wikipedia.org/wiki/Magnetic_domain
http://ischuller.ucsd.edu/research/EB-Fig1.jpg
Magnetization of an Fe single crystal at T<Tc
Easy axis
Fe: bcc close packing
Fe (bcc structure)
Ni (fcc structure)
Co (hex. structure)
http://nptel.ac.in/courses/115103038/module1/lec3/images/image007.png
Magnetic hysteresis loop
Coherent rotation of domains
Irreversible wall displacements
Reversible wall displacements
Virgin curve
(1)
(1) Domains with M II H grow on cost of others
(2) domains rotate irreversibly along easy axis
(3) as soon as only one domain is left, it rotates along H
Anisotropy in Nd-Fe-B
D. Goll and H. Kronmüller, Naturwissenschaften 87, 423 (2000).
Microstructure and it‘s impact on magnetic hysteresis
D. Goll and H. Kronmüller, Naturwissenschaften 87, 423 (2000).
http://openstudy.com/study#/updates/4fc4d292e4b0964abc872b53