Fluorite-type Ce0.5Zr0.5O2 and Ce0.5Hf0.5O2 have been synthesized by a solution combustion route, and their oxygen release and reduction have been investigated up to 850 degrees C. On reduction, the zirconium system forms two pyrochlore phases, Ce2Zr2O7 (pyrochlore-I) and Ce2Zr2O6.2 (pyrochlore-II), while the hafnium system forms only a disordered fluorite phase with the composition Ce0.5Hf0.5O...

Chiral group 4 NHC-metal complexes were prepared in good yields by amine elimination from M(NR2)4 (M = Ti, Zr, Hf; R = Me, Et) and chiral pincer NHC-ligands, L4(L4a and L4b), L5 and L6, which are derived from (S,S)-diphenyl-1,2-ethanediamine. Treatment of M(NR2)4 with 1 equiv. of L4 in THF gives, after recrystallization from a benzene solution, the chiral titanium amides (L4)Ti(NMe2)(Br)(THF) (...

Hafnium oxide interfaces were studied on two related group III rich semiconductor surfaces, InAs(0 0 1)-(4x2) and In(0.53)Ga(0.47)As(0 0 1)-(4x2), via two different methods: reactive oxidation of deposited Hf metal and electron beam deposition of HfO(2). The interfaces were investigated with scanning tunneling microscopy and spectroscopy (STS). Single Hf atom chemisorption sites were identified...

Crystalline phase identification for hafnium-based ferroelectrics by diffraction techniques has been elusive. We use density-functional-theory (DFT)-assisted extended X-ray absorption fine-structure spectroscopy (EXAFS) to determine the crystal symmetry of thin hafnium zirconium oxide (Hf0.46Zr0.54O2) films grown atomic layer deposition. Ferroelectric switching in TiN/Hf0.46Zr0.54O2/TiN metal–i...

Establishing the age of the Moon is critical to understanding solar system evolution and the formation of rocky planets, including Earth. However, despite its importance, the age of the Moon has never been accurately determined. We present uranium-lead dating of Apollo 14 zircon fragments that yield highly precise, concordant ages, demonstrating that they are robust against postcrystallization ...

Negative ion photoelectron spectra of ZrO(-), HfO(-), HfHO(-), and HfO(2)H(-) are reported. Even though zirconium- and hafnium-containing molecules typically exhibit similar chemistries, the negative ion photoelectron spectral profiles of ZrO(-) and HfO(-) are dramatically different from one another. By comparing these data with relevant theoretical and experimental studies, as well as by using...

• Group IV metal oxo clusters (MOCs) applications in materials and catalysis are rapidly expanding. MOCs prepared aqueous or organic medium with a variety of ligands. Ligands influence structure properties, thus impacting syntheses catalysis. Ligand-exchanged happens without rearrangement the inorganic core. (IV) diverse class compounds growing catalysis, chemistry, electronics optics. They pos...

Hf-phosphinoamide cation complexes behave as metal-based frustrated Lewis pairs and bind one or two equivalent of CO2 and in as well can activate CO2 in a bimetallic fashion to give a pseudo-tetrahedral P2CO2 fragment linking two Hf centres.