The most remarkable advance that one can report as regards transuranium systems is certainly the discovery of superconductivity above 18 K in PuCoGa5. Motivated by this discovery, we have investigated bulk samples of both PuCoGa5 and its Rh analogue. Characterizations of polycrystalline Co and Rh compounds are reported. The new PuRhGa5 compound is also found to become superconducting above 8 K.

We carried out a complete study (magnetic, electronic, dielectric, dynamic, and elastic properties) of the nickel hydroxide [Ni(OH)2] from first-principles calculations based on density functional theory. No theoretical investigations of these physical properties have been previously reported in literature. Our work supports that Ni(OH)2 is an A-type antiferromagnetic material. In addition, it is negative uniaxial and semiconducting with a direct band gap at the Γ point around 3 eV. By contrast to its electronic dielectric tensor, its static tensor is strongly anisotropic in the plane orthogonal to its optical axis. This anisotropy is mainly governed by a highly polar phonon centered around 510 cm−1 and assigned as a rotational Eu mode. Both Raman and infrared spectra have been computed to clarify the longstanding debate on the assignment of the Ni(OH)2 phonon modes reported in literature. All these theoretical results are fruitfully compared to the experimental ones obtained on large Ni(OH)2 "pseudosingle" crystals when available

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In 1928, Zachariasen discovered the LiNbO 3 phase. [1] The first single crystals were grown using the flux method by Matthias Over the past five decades, LiNbO 3 and LiTaO 3 single crystals and thin films have been studied intensively for their exceptional acoustic, electro-optical, and pyroelectric and ferroelectric properties. Today, LiNbO 3 single crystals in electro-optics are equivalent to silicon in electronics, and about 70% of radio-frequency (RF) filters, based on surface acoustic waves, are fabricated on these single crystals. These materials in the form of thin films are needed urgently for the development of the next-generation of high-frequency and/or wide-band RF filters or tuneable frequency filters adapted to the fifth generation of infrastructures/networks/communications. The integration of LiNbO 3 films in guided nanophotonic devices will allow higher operational frequencies, wider bandwidth, and miniaturized optical devices in line with improved electronic conversion. Here, the challenges and the achievements in the epitaxial growth of LiTaO 3 and LiNbO 3 thin films and their integration with silicon technology and to acoustic and guided nanophotonic devices are discussed in detail. The systematic representation and classification of all epitaxial relationships reported in the literature have been carried out in order to help the prediction of the epitaxial orientations in the new heterostructures. Future prospects of potential applications and the expected performances of thin film devices are overviewed, as well.Figure 2. Schematic representation of the layer transfer process by the ion slicing technique consisting of a) ion implantation, b) wafer bonding, c) laser irradiation or heating in order to obtain d) a single crystalline layer on the host (Si) substrate. Reproduced with permission. [53]Figure 3. a,b) Electron microscopy images and c) schematic diagram of a microresonator based on LiNbO 3 film on Si and fabricated by the layer transfer technique. Reproduced with permission. [53]The first reports on the growth of c-axis-oriented LN films by liquid phase epitaxy on an LT substrate and by RF sputtering Adv. Mater. Interfaces 2017, 4, 1600998 www.advmatinterfaces.de www.advancedsciencenews.com Figure 6. Frequency response of a) HBAR and b) FBAR based on thinned X-cut LiNbO 3 layer on Si. Schematic representations of a) HBAR and b) FBAR structures are given in the insets. Reproduced with permission. [78]