Large Anomalous Hall Effect in a Nanocrystalline Room-Temperature Ferromagnetic CoCrFeNiGa High-Entropy Alloy.

Magnetic high-entropy alloys (HEAs) with their unusual blend of long-range magnetic order and exceptional mechanical properties are beneficial for the development of next-generation spintronic devices that can withstand extreme conditions. Developing room-temperature magnetic HEAs and understanding the link among their magnetic, electronic, and mechanical properties are crucial. Here, we introduce nanocrystalline CoCrFeNiGa as a room-temperature bulk magnetic HEA candidate based on 3d-transition metals and elucidate its magnetic and electronic properties.

Machine learning for the development of new materials for a magnetic tunnel junction.

In materials science, we have been increasing the number of constituent elements in an alloy and compounds to improve their properties. For example, in magnetism and spintronics, ternary alloys, such as NdFeB and CoFeB have been developed and widely used in permanent magnets and memories/sensors, respectively. It has now been considered to be a time to add more elements to further explore their horizon.

Strong antiferromagnetic interlayer exchange coupling induced by small additions of Re to an Ir interlayer in synthetic antiferromagnetic systems.

Synthetic antiferromagnetic (AF) pinned layers are widely used in order to reduce the stray field of the pinned layer and stabilize the magnetic alignment of the reference layer in perpendicular magnetic tunnel junctions (MTJs). Here, a detailed study of Re concentration dependence of the magnitude of interlayer exchange coupling (|J|) in a synthetic AF system with an Ir-Re interlayer is conducted. We observed strong AF interlayer exchange coupling caused by small amounts of Re addition and phase shift of the AF peak to thinner interlayer region in synthetic AF systems with Ir-Re interlayer.

Metastable body-centered cubic CoMnFe alloy films with perpendicular magnetic anisotropy for spintronics memory.

A body-centered cubic (bcc) FeCo(B) is a current standard magnetic material for perpendicular magnetic tunnel junctions (-MTJs) showing both large tunnel magnetoresistance (TMR) and high interfacial perpendicular magnetic anisotropy (PMA) when MgO is utilized as a barrier material of -MTJs. Since the -MTJ is a key device of current spintronics memory, . spin-transfer-torque magnetoresistive random access memory (STT-MRAM), it attracts attention for further advance to explore new magnetic materials showing both large PMA and TMR.

study of electronic and magnetic properties of MnRu/MgO (001) heterojunctions (Al, Ge).

We studied the applicability of Heusler alloys MnRu(= Al, Ga, Ge, Si) to the electrode materials of MgO-based magnetic tunnel junctions. All these alloys possess HgCuTi-type inverse Heusler alloy structure and ferrimagnetic ground state. Our study reveals the half-metallic electronic structure with highly spin-polarized Δband, which is robust against atomic disorder.

Magnetic properties and electronic structure of Mn-Ni-Ga magnetic shape memory alloys.

Influence of disorder, antisite defects, martensite transition and compositional variation on the magnetic properties and electronic structure of Mn(2)NiGa and Mn(1+x)Ni(2-x)Ga magnetic shape memory alloys have been studied by using full potential spin-polarized scalar relativistic Korringa-Kohn-Rostocker (FP-SPRKKR) method. Mn(2)NiGa is ferrimagnetic and its total spin moment increases when disorder in the occupancy of MnNi (Mn atom in Ni position) is considered. The moment further increases when Mn-Ga antisite defect [1] is included in the calculation.