A Room-Temperature Ferrotoroidic Material Exhibiting Magnetic Semiconductor Properties with Superhigh Hole Mobility

Abstract

The design and fabrication of room-temperature ferrotoroidic materials and magnetic semiconductors are recognized worldwide as a great challenge, and of both theoretical and practical importance in the field of condensed matter physics and information storage. Reported herein are ferrotoroidic crystal powder and film formed by supramolecular self-assembly based on uranyl and cyclodextrin, with the Curie temperature above room temperature. Experimental measurements and calculations demonstrate spontaneous vortex-like alignment of magnetic moments and furthermore a macroscopic long-range arrangement in the crystal, which breaks simultaneously space-inversion and time-reversal symmetries, exhibiting strong superexchange, spin-orbit coupling as well as anomalous Hall effect (AHE). The electrical measurements show the film with a superhigh carrier mobility of 3200 cm2*V-1*s-1 and a Hall resistivity as high as 0.32 mV*A-1*cm at room temperature. This work is expected to pave greatly the applied research on new-generation magnetoresistive random access memory (MRAM), especially as flexible material.