Highly compact green bodies are usually required to fabricate transparent or translucent polycrystalline yttrium oxide. The present work reports on the fabrication of highly dense (ρrel >98%) Y2O3 from low-density by exploiting a high sinterability nano powder. A commercial Y2O3, with crystallite size ca. 30 nm, was shaped uniaxial pressing and, afterwards, densified pre-sintering at 1500 °C fo...

Densification of cuboidal micrometer-sized lithium fluoride particles as ductile ceramic by spark plasma sintering (SPS) was investigated. Specimens were fabricated at different pressures and temperature conditions, ranging from 2 to 100 MPa at 500 C and from 200 to 700 C under 100 MPa of applied pressure, respectively. Dense specimens of 99 % relative density were fabricated by heating to 500 ...

An alumina–zirconia composite containing 5 mol% zirconia was prepared by following a wet interaction process in aqueous medium via the sol–gel route. The formed hydrogel which was aged for proper growth and orientation at room temperature, was then dried at a low temperature to minimize agglomeration. The sol–gel derived precursor powder was properly characterized through determination of surfa...

A mixed proton–electron conducting perovskite was synthesized by liquid-citrate method and the corresponding membrane was prepared by pressing followed by sintering. The hydrogen permeability of BaCe0.9Yb0.1O3-δ was studied as a function of temperature and hydrogen partial pressure (PH2) gradient. Using 100% dry hydrogen at 1173 K, the hydrogen permeation rate of dense membranes (1.63 mm thick)...

A new family of perovskites RMnMnTaO6 has been synthesised at high pressure for representative R ?= ?La, Nd, Sm, Eu, Gd, Y and Lu that span the whole rare earth series. The structure type changes from tetragonal P42/n double perovskite (DDPv) with columnar R3+/Mn2+ cation order (R Sm) to monoclinic P21/n (DPv) (R0.5Mn0.5)2MnTaO6 ?Sm, Y, Lu) as R3+ size decreases. No antisite disorder or nonstoi...

Transparent ytterbium-doped yttria ceramics, 2 at.% Yb:Y2O3, were fabricated by hot uniaxial pressing in vacuum at 1550 °C/50 MPa followed a two-stage Hot Isostatic Pressing (HIPing) 1200–1400 °C/100 MPa, using nanopowders obtained self-propagating high-temperature synthesis (with lithium fluoride serving as sintering aid). The addition of LiF during the powder markedly changed morphology powde...

The aim of this paper is to introduce and study a new concept ofstrong double $(A)_ {Delta}$-convergent sequence offuzzy numbers with respect to an Orlicz function and also someproperties of the resulting sequence spaces of fuzzy   numbers areexamined. In addition, we define the double$(A,Delta)$-statistical convergence of fuzzy  numbers andestablish some connections between the spaces of stron...