In an amorphous microwire, the magnetic domain structure is such that the magnetic core of the wire (in a glass coating) has two parts: an inner core with the single-domain system, and the outer core with multiple closure domains.
The drawing was based on: J. Olivera et al., "Temperature Dependence of the Magnetization Reversal Process and Domain Structure in Fe(77.5-x)Ni(x)Si(7.5)B(15) Magnetic Microwires," IEEE Transactions on Magnetics, vol. 44, no. 11, pp. 3946-3949, Nov. 2008, doi: 10.1109/TMAG.2008.2002194