Colossal Magnetoresistive Switching Induced by d Ferromagnetism of MgO in a Semiconductor Nanochannel Device with Ferromagnetic Fe/MgO Electrodes.

Exploring potential spintronic functionalities in resistive switching (RS) devices is of great interest for creating new applications, such as multifunctional resistive random-access memory and novel neuromorphic computing devices. In particular, the importance of the spin-triplet state of cation vacancies in oxide materials, which is induced by localized and strong O-2p on-site Coulomb interactions, in RS devices has been overlooked. d ferromagnetism sometimes appears due to the spin-triplet state and ferromagnetic Zener's double exchange interactions between cation vacancies, which are occasionally strong enough to make nonmagnetic oxides ferromagnetic.

Insight into Scattering Mechanisms and Transport Properties of AgCuS for Flexible Thermoelectric Applications.

The development of flexible thermoelectric devices requires materials possessing ductility and high thermoelectric performance at room temperature. However, only a few existing materials meet both criteria. In this study, the ductile properties, electronic structure, and transport properties of the low-temperature phase α-AgCuS were elucidated using first-principles calculations combined with Boltzmann transport theory.

Ferromagnetism and giant magnetoresistance in zinc-blende FeAs monolayers embedded in semiconductor structures.

Material structures containing tetrahedral FeAs bonds, depending on their density and geometrical distribution, can host several competing quantum ground states ranging from superconductivity to ferromagnetism. Here we examine structures of quasi two-dimensional (2D) layers of tetrahedral Fe-As bonds embedded with a regular interval in a semiconductor InAs matrix, which resembles the crystal structure of Fe-based superconductors. Contrary to the case of Fe-based pnictides, these FeAs/InAs superlattices (SLs) exhibit ferromagnetism, whose Curie temperature (T) increases rapidly with decreasing the InAs interval thickness t (T ∝ t), and an extremely large magnetoresistance up to 500% that is tunable by a gate voltage.

Intrinsic defect formation and the effect of transition metal doping on transport properties in a ductile thermoelectric material α-AgS: a first-principles study.

In this paper, the electronic structure and transport properties of a ductile thermoelectric material α-Ag2S are examined using first-principles calculations combined with the Boltzmann transport equation within a constant relaxation-time approximation. The use of the exchange-correlation functional SCAN + rVV10 successfully describes the geometric and electronic structure of α-Ag2S with a direct bandgap value of 0.99 eV, which is consistent with the previous experimental observations.

Hole-mediated ferromagnetism in a high-magnetic moment material, Gd-doped GaN.

As an exotic material in spintronics, Gd-doped GaN is known as a room temperature ferromagnetic material that possesses a large magnetic moment (4000per Gd ion). This paper theoretically proposes that the large magnetic moment and room temperature ferromagnetism observed in Gd-doped GaN is caused by N 2p holes based on the assumption that Ga-vacancies result from the introduction of Gd ions. This causes that the too large magnetic moment is estimated for Gd ions if only Gd ions contributed the magnetic moment.