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We propose a new type of magnetoelectric memory device that stores magnetic easy-axis information or pseudo-magnetization, rather than a definite magnetization direction, in magnetoelectrically coupled heterostructures. Theoretically, we show how a piezoelectric/ferromagnetic (PE/FM) combination can lead to non-volatility in pseudo-magnetization exhibiting overall ferroelectric-like behavior. The pseudo-magnetization can be manipulated by extremely low voltages especially when the FM is a low-barrier nano-magnet. Using a circuit model benchmarked against experiments, we determine the switching energy, delay, switching probability and retention time of the envisioned 1T/1C memory device in terms of magnetic and circuit parameters and discuss its thermal stability in terms of a key parameter called back-voltage vm which is an electrical measure of the strain-induced magnetic field. Taking advantage of ferromagnetic resonance measurements, we experimentally extract values for vm in CoFeB films and circular nano-magnets deposited on Pb(Mg1/3Nb2/3)0.7Ti0.3O3 which agree well with the theoretical values. Our experimental findings indeed indicate the feasibility of the proposed novel device and confirm the assumed parameters in our modeling effort. [ABSTRACT FROM AUTHOR]

Investigates the resonant magnetization tunneling process involved in the trigonal pyramidal manganese complex. Equation for the complex; Reference to the magnetic properties of single molecule magnets; Indentification of single-molecule magnets; Methods used to conduct studies on single-molecule magnets.

We report different growth modes and corresponding magnetic properties of thin EuSe films grown by molecular beam epitaxy on BaF2, Pb1−xEuxSe, GaAs, and Bi2Se3 substrates. We show that EuSe grows predominantly in the (001) orientation on GaAs(111) and Bi2Se3, but along the (111) crystallographic direction on BaF2 (111) and Pb1−xEuxSe (111). High resolution transmission electron microscopy measurements reveal a sharp and highly crystalline interface for both (001) and (111) EuSe films. In agreement with previous studies, ordered magnetic phases include antiferromagnetic, ferrimagnetic, and ferromagnetic phases. In contrast to previous studies, we found a strong hysteresis of the antiferromagnetic–ferrimagnetic transition. The ability to grow epitaxial films of EuSe on Bi2Se3 and of Bi2Se3 on EuSe enables further investigation of interfacial exchange interactions between various phases of an insulating metamagnetic material and a topological insulator. [ABSTRACT FROM AUTHOR]

Presents information regarding the chemical aspects involving the nanoscale magnets. Identification of fabrication techniques; Verification of macroscopic measurement of a molecular tunneling event; Information on the resonant magnetization tunneling.

Magnetization measurements of soft-magnetic materials can be affected if they are characterized using a superconducting solenoid. Recording hysteresis loops while stepping the magnetic field can cause an apparently inverted hysteresis, if due to the pinned remanent flux in the magnet the field at the sample location exceeds the sample’s coercive field. Hysteresis loops recorded while sweeping the field can also be affected by ramping rate. The sweeping-rate dependence is caused by leakage currents resulting from the persistent switch and synchronization issues regarding collection of magnetic moment and field data. The resulting errors can be estimated by measuring paramagnetic dysprosium oxide. [ABSTRACT FROM AUTHOR]

• A new thermoelectric cement composite enhanced by graphite and MnO 2. • Simultaneous measurement of thermoelectric properties for cement composites. • Impacts of dry mixing and wet mixing on samples' TE performance. • Impacts of additives' concentrations and electrical contact resistance. Thermoelectric cement, the mixture of cement and thermoelectric additives, can convert energy between thermal and electrical forms due to the thermoelectric additives. Potentially, they could be the material for building envelopes to harvest waste heat and/or provide space cooling or heating. When there is a significant difference between indoor and outdoor temperatures, the thermoelectric cement can generate electricity using the temperature gradient. And the same material can cool or heat building space via building envelopes with an electrical input. The research aimed to identify and characterize thermoelectric cement candidates for building envelope applications. The additives used in the studied thermoelectric cement candidates include graphite and MnO 2. Except for the additives, the study also explored the impact of the two different fabrication methods: wet-mixing and dry-mixing on thermoelectric performance. The images of TE cement candidates taken by scanning electron microscopy and energy dispersive X-ray microscopy visualized the morphology and distribution of additives in the thermoelectric cement composites. The DynaCool Physical Properties Measurement System used in the study simultaneously measured the candidates' thermoelectric properties, including thermal conductivity, electrical conductivity, Seebeck coefficient, and Figure of merit (ZT). The test results showed that the thermoelectric cement with the additives of 10% (weight ratio) graphite and 5% MnO 2 has the highest ZT of 6.2 × 10−6 at 350 K. ZT of the thermoelectric cement is even higher to 10−5 orders of magnitude when applying a four-probe electrical resistivity method to account for the contact resistance. [ABSTRACT FROM AUTHOR]

Depth profiles for pinned and unpinned magnetizations were determined across the interface between a ferromagnet (F) and random and dilute antiferromagnets (RAF and DAF) exemplified by Fe0.45Ni0.55F2/Co and Fe0.45n0.66F2/Co bilayers, respectively, using polarized neutron reflectivity (PNR). PNR measurements were complemented by magnetometry using applied fields as large as 160 kOe to assure saturation of the entire sample, including magnetic moments that are normally pinned at lower fields. The locations of pinned and unpinned magnetization in the ferro- and antiferromagnets were identified. The origin of exchange bias in the RAF system is noticeably different than that of the DAF system. In the RAF system, a domain wall is formed at the RAF/F interface when the ferromagnet's magnetization is reversed. In the DAF system, some domains within the bulk of the DAF are reversed upon reversal of the ferromagnet while others remain pinned. In this case, the interface magnetization is entirely reversed. [ABSTRACT FROM AUTHOR]