A large body of work has been reported in the last 5 years on development lead‐free piezoceramics quest to replace lead–zirconate–titanate (PZT) as main material for electromechanical devices such actuators, sensors, and transducers. In specific but narrow application ranges new materials appear adequate, are not yet suited PZT a broader basis. this paper, general guidelines piezoelectric ceramics presented. Suitable chemical elements selected first basis cost toxicity well ionic...

The depolarization temperature Td of piezoelectric materials is an important figure merit for their application at elevated temperatures. Until now, there are several methods proposed in the literature to determine piezoelectrics, which based on different physical origins. Their validity and inter-correlation have not been clearly manifested. This paper applies definition as steepest decrease remanent polarization evaluates currently used methods, both terms this practical applicability. For...

A high‐temperature dielectric, (1– x )(0.6 Bi 1/2 Na TiO 3 –0.4 K )– 0.5 NbO , off the morphotropic phase boundary of parent matrix 0.8 –0.2 has been developed for application as a capacitor. In addition to temperature‐dependent permittivity and dielectric loss, DC conductivity field‐dependent are reported. These properties correlated with structure data measured at different length scales using Raman spectroscopy neutron diffraction. It is suggested that all materials investigated ergodic...

The structural behavior of ceramic solid solutions (1\ensuremath{-}$x$)Na${}_{1/2}$Bi${}_{1/2}$TiO${}_{3}$--$x$K${}_{1/2}$Bi${}_{1/2}$TiO${}_{3}$ (NBT-KBT) was studied using high-resolution powder diffraction and transmission electron microscopy. A temperature-independent morphotropic phase boundary (MPB) separating NBT-like pseudorhombohedral (R) KBT-like pseudotetragonal (T) phases observed at $x$ \ensuremath{\approx} 0.2. For $x<0.2$, both local average room-temperature structures are...

SmN is ferromagnetic below 27 K, and its net magnetic moment of 0.03 Bohr magnetons per formula unit one the smallest magnetizations found in any material. The near-zero a result nearly equal opposing spin orbital moments ${}^{6}$H${}_{5/2}$ ground state Sm${}^{3+}$ ion, which leads finally to complete cancellation for an ion state. Here we explore alignment this compound with x-ray circular dichroism at Sm L${}_{2,3}$ edges. spectral shapes are qualitative agreement computed spectra based...

Europium nitride is semiconducting and contains nonmagnetic ${\mathrm{Eu}}^{3+}$, but substoichiometric EuN has Eu in a mix of $2+$ $3+$ charge states. We show that at ${\mathrm{Eu}}^{2+}$ concentrations near 15%--20% ferromagnetic with Curie temperature as high 120 K. The ${\mathrm{Eu}}^{3+}$ polarization follows the ${\mathrm{Eu}}^{2+}$, confirming ferromagnetism intrinsic to which is, thus, novel diluted magnetic semiconductor. Transport measurements shed light on likely exchange mechanisms.

Ferromagnetism and superconductivity are two generally incompatible states of matter. Their coexistence has been observed only under very unusual circumstances so far in metals. In contrast, most semiconductors not naturally magnetic or superconducting, but introducing magnetism into is seen as an important step towards radical improvement our electronics capabilities therefore a hotly pursued goal. Here, the authors report discovery coexisting with ferromagnetism semiconducting material...

Lead-free (1- y )(Bi 1/2 Na TiO 3 – x Bi K )– 0.5 NbO [(1- )(BNT– BKT)– KNN] (0.1≤ ≤0.6 and 0≤ ≤0.05) ceramics were prepared with compositions both at as well off the morphotropic phase boundary (MPB) of =0.2 =0. It was found that KNN addition destabilizes a ferroelectric order in BNT–BKT zero electric-field, resulting low remanent polarization, strain effective small signal d 33eff [23 pC/N for ( , )=(0.2,0.05), 60 (0.2, 0.02)], while it does not affect maximum polarisation high fields thus...

The rare-earth nitrides have recently regained attention due to findings that most members of the series are intrinsic ferromagnetic semiconductors, a class materials is crucial for development spintronics devices. Here we present study NdN thin films, with films grown via molecular beam epitaxy. Optical transmission measurements revealed band gap about 0.9 eV, while resistivity confirmed semiconducting behavior negative temperature coefficient resistance, though semimetallic could not be...

The strong spin-orbit interaction in the rare-earth elements ensures that even within a ferromagnetic state there is substantial orbital contribution to moment, contrast more familiar transition metal systems, where moment usually quenched. orbital-dominant magnetization then possible systems facilitates fabrication of entirely new magnetic heterostructures, and here we report study particularly striking example comprising interfaces between GdN SmN. Our investigation reveals twisted arising...

A numerical method is presented to predict the effect of microstructure on local polarization switching bulk ferroelectric ceramics. The model shows that a built-in electromechanical field develops in material as result spatial coupling grains and direct physical between thermomechanical properties ceramic material. fields from thermomechanically induced grain-grain interactions appearance four microstructural mechanisms: (1) simple switching, where c-axes domains will align with direction...

We demonstrate a nonvolatile cryogenic magnetic memory element needed to support emerging superconducting- and quantum-computing technologies. The central is switchable tri-layer thin film dot comprising two semiconducting ferromagnetic GdxSm1−xN layers separated by an exchange-blocking Al layer. materials are explored for their tunable responses, the potential engineer compensating moments in anti-parallel tri-layers. stability of parallel states reproducibility over repeated cycles also...

Using modern thin film growth techniques, and performing structural, magnetic, optical electrical transport measurements on YbN films, the authors show that these films are antiferromagnetic semiconducting, unlike other rare-earth nitrides either para- or ferromagnetic.

Epitaxial growth of (100)-oriented rare-earth nitrides (RENs) SmN, GdN, and DyN on (100)LaAlO3 (LAO) substrates is demonstrated using molecular beam epitaxy. RHEED ϕ-scans confirm that the cubic RENs grow 45° rotated with respect to pseudocubic (100)-surface LAO, which leads lattice mismatches between −5.8% −8.7% for selected RENs. Those mismatches, despite being significant, are smaller than in previously reported epitaxial (100)RENs, exception (100)YSZ (yttria stabilized zirconia), however...

We report electrical transport and optical spectroscopy measurements on LuN thin films variously doped with nitrogen vacancies along the computed band structures of stoichiometric vacancy LuN. has been subject several recent computational studies; however, most experimental studies regarding its electronic properties are already over four decades old. Here, we bridge void between computation experiment a combined study focusing properties. find that is semiconductor an bandgap ∼1.7 eV. Its...

Lead-free (1-y)(Bi1/2Na1/2TiO3–xBi1/2K1/2TiO3)–yK0.5Na0.5NbO3 [(1-y)(BNT–xBKT)–yKNN] (0.1≤x≤0.6 and 0≤y≤0.05) ceramics were prepared with compositions both at as well off the morphotropic phase boundary (MPB) of x=0.2 y=0. It was found that KNN addition destabilizes a ferroelectric order in BNT–BKT zero electric-field, resulting low remanent polarization, strain effective small signal d33eff [23 pC/N for (x,y)=(0.2,0.05), 60 (0.2, 0.02)], while it does not affect maximum polarisation high...

We demonstrate growth of epitaxial (100)SmN thin films directly on (100)Si surfaces. By using physical vapor deposition Sm metal in an ${\mathrm{N}}_{2}$ atmosphere we show that careful control substrate temperature, pressure, and postannealing steps leads to SmN without the formation samarium silicide impurity phases. While rare-earth competes with is favored over nitride at high temperatures, find low-temperature grown seed layers are stable against high-temperature annealing, thus allow...

We report twisted magnetization phases, i.e., exchange springs, across interfaces in a semiconducting NdN/GdN superlattice and compare the springs to those reported previously SmN/GdN interfaces. Like SmN, NdN has an orbital moment larger than opposing its spin magnetic moment, resulting exchange-Zeeman competition that turn precipitates springs. In contrast large net adding more complexity exchange-spring behavior. investigate how different temperatures applied fields influence using...

GdN and SmN are two of the lanthanide nitrides, most which intrinsic ferromagnetic semiconductors. Superlattices comprising pair offer a unique opportunity to investigate heterojunctions that feature simultaneous conductivity magnetic interface influences. Here we report an investigation these influences, using magnetisation X-ray circular dichroism for effects, magnetoresistance Hall effect studies their electrical conductance. Magnetic data show clear signatures conflicting Zeeman vs....

SessionsC695 microscope (TEM) fitted with a spherical aberration corrector on the probe forming lens to minimize effect of aberrations Fourier image.As expected, these images bring different spatial frequencies into focus for cross-over positions above specimen.Under certain conditions, this enables specific families atomic planes be imaged individually.We discuss how phenomenon can used image crystal defects in coherent CBED patterns.Furthermore, we show how, by using an appropriately...