The fuorides K3Fe5F15 and K3Cr2Fe3F15 are known as multiferroic materials. We reported the detection of a magnetic memory effect in these materials and its dependence on temperature and aging time. We succeeded in writing, reading, and deleting 3bits of digital information in these systems. These results show that in addition to their already known magnetoelectric multiferroic properties, K3Fe5F15 and K3Cr2Fe3F15 also possess a new functionality: they can be used as materials for a thermal memory cell.
COBISS.SI-ID: 26820647
By investigating the magnetism of spins on a quasiperiodic lattice, we presented an experimental study of static and dynamic magnetic properties, specifc heat, and magnetic entropy of the Gd3Au13Sn4 quasicrystalline approximant. The magnetic sublattice of Gd3Au13Sn4 is a periodic arrangement of nonoverlapping spin clusters of almost perfect icosahedral symmetry, where gadolinium localized f magnetic moments are distributed on equilateral triangles. We demonstrated that the spin system undergoes at low temperatures a transition to a nonergodic state at the spin freezing temperature Tf =2.8 K. Below this, the ergodicity is broken on the experimental timescale, because the thermally activated correlation times for the spin reorientations become macroscopically long. The magnetic properties of the siteordered, geometrically frustrated Gd3Au13Sn4 system are discussed in comparison to sitedisordered spin glasses that contain both randomness and frustration.
COBISS.SI-ID: 27364391
Spinglass properties of magnetic quasicrystals with spins placed on a quasiperiodic lattice, and complex metallic alloys, characterized by giant unit cells, are reviewed. The systems exhibit rich variety of brokenergodicity phenomena that share properties with sitedisordered canonical spin glasses and siteordered geometrically frustrated antiferromagnets. Magnetic frustration provides basis of a novel concept of digital data storage, where a byte of digital information can be stored into the material by pure thermal manipulation, in the absence of electric, magnetic or electromagnetic field.
COBISS.SI-ID: 25725991
Searching for a novel magnetic material for thermal storage of digital information, we have investigated ironcontaining compounds FeAl2 and Fe2Al5. We found that thermal inscription of digital information is possible at higher temperatures than in the CuMn spin glass.
COBISS.SI-ID: 24856359
We present the synthesis, characterization, and magnetic properties of hematite particles in a peculiar “nanomedusa” morphology. The “hairy” particles consist of a spherical-like core of about 100 nm diameter and fibrous exterior composed of thin “legs” of 5 nm diameter grown along one preferential direction. A measured deviation of the ZFC and FC susceptibility below 650 K reveals a non-ergodic state of the system already at room temperature which is a prerequisite for using a material as a TMC at room temperature.
COBISS.SI-ID: 28173095