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A laboratory-scale process is described for recycling rare earth metals from end-of-life rare-earth/iron/boron alloy permanent magnets using a 2 h chlorine gas treatment at 673 K. This treatment does not require any special preparation of the magnets; they can be used without demagnetisation, crushing or milling. Following treatment at 673 K, a clinker powder consisting of rare earth metal chlorides with minimal amounts of other metals is obtained, while haematite and iron oxychloride sublimate. Following literature sources, it is suggested that the rare earth metal chlorides in the clinker may be readily reduced to metal, either by electrolysis in relatively low temperature eutectic melts or by metallothermic reduction in mixtures with alkali or alkaline earth metals. (Authors.), A laboratory-scale process is described for recycling rare earth metals from end-of-life rare-earth/iron/boron alloy permanent magnets using a 2 h chlorine gas treatment at 673 K. This treatment does not require any special preparation of the magnets; they can be used without demagnetisation, crushing or milling. Following treatment at 673 K, a clinker powder consisting of rare earth metal chlorides with minimal amounts of other metals is obtained, while haematite and iron oxychloride sublimate. Following literature sources, it is suggested that the rare earth metal chlorides in the clinker may be readily reduced to metal, either by electrolysis in relatively low temperature eutectic melts or by metallothermic reduction in mixtures with alkali or alkaline earth metals. (Authors.)

Surface pyroelectricity and piezoelectricity induced by water incorporation during growth in α-glycine were investigated. Using the periodic temperature change technique, we have determined the thickness (~280 µm) of the near surface layer (NSL) and its pyroelectric coefficient (160 pC/(K × cm2) at 23◦C) independently. The thickness of NSL remains nearly constant till 60◦C and the pyroelectric effect vanishes abruptly by 70◦C. The piezoelectric effect, 0.1 pm/V at 23◦C measured with an interferometer, followed the same temperature dependence as the pyroelectric effect. Abrupt disappearance of both effects at 70◦C is irreversible and suggests that water incorporation to α-glycine forms a well defined near surface phase, which is different form α-glycine because it is polar but it too close to α-glycine to be distinguished by X-ray diffraction (XRD). The secondary pyroelectric effect was found to be <14% of the total, which is unexpectedly small for a material with a large thermal expansion coefficient. This implies that water incorporation infers minimal distortions in the host lattice. This finding suggests a path for the control of the piezoelectric and pyroelectric effects of the crystals using stereospecific incorporation of the guest molecules. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Cerium oxide (CeO) has a wide range of different applications such as gas sensing, water splitting and others. CeO is an attractive alternative to yttria-stabilized zirconia as an electrolyte for low-temperature fuel cells because of its high ionic conductivity, low reactivity and good chemical compatibility with many mixed conducting cathode materials [1].

We present the results of studying piezoelectric properties in pure DL-alanine and α-glycine crystals doped with amino acids: L-alanine, L-serine, and phase transformations in pure DL-alanine crystals. Crystals were provided by Weizmann Institute of Science. Piezoelectric properties have been measured with high spatial resolution by piezoresponse force microscopy (PFM) using Asylum MFP 3D (Asylum Research, USA). Phase transformation was visualized by PFM.

Highly sensitive laser interferometer was built to measure electromechanical coupling in Gd-doped ceria Ce0.9Gd0.1O2−x thin films in the frequency range up to 20 kHz. Spurious resonances due to substrate bending were avoided by the special mounting of the film in the center of substrate. Compact design allowed to reach high vertical resolution of about 0.2 pm. Electrostriction coefficient measured in 1 μm thick Ce0.9Gd0.1O2−x film was 4.3×10−21m2/V2 and slightly decreased with frequency till the extensional resonance of the substrate at about 20 kHz occurred. As expected, the displacement varied as a square of applied voltage without any sign of saturation. A comparison with ceramics showed much higher electrostriction coefficient in the latter in the same frequency range.