Blar i NTNU Open på forfatter "Wiik, Kjell"
-
Microstructural design of CaMnO3 and its thermoelectric proprieties.
Mazur, Natalia Maria (Master thesis, 2015)Calcium manganate (CMO) is an n-type semiconductor with promising thermoelectric proprieties. Solid state synthesis was employed to synthesise the desired material in two phases: i) reduced rock-salt phase of CaO-MnO (ss) ... -
Microstructural Stability of Tailored CaMn0.875−xFexTi0.125O3−δ Perovskite Oxygen Carrier Materials for Chemical Looping Combustion
Thoréton, Vincent; Pishahang, Mehdi; Mokkelbost, Tommy; Wiik, Kjell; Larring, Yngve (Journal article; Peer reviewed, 2017)CaMn1−xTixO3−δ are state-of-the-art perovskite-type oxygen-carrier materials (OCMs) used in gaseous fluidized-bed chemical looping combustion (CLC), which is currently undergoing upscaling and demo campaigns in several ... -
Nanostructuring of Oxygen Permeable Membranes by Chemical Etching Techniques
Wefring, Espen Tjønneland (Master thesis, 2011)Mixed ionic electronic conducting ceramic oxides are being investigated for use as membranes for oxygen separation from air and as electrodes in solid oxide fuel cells [1, 2]. Oxygen surface exchange rate is an important ... -
Optimization of Strength and Permeability of Tape casted Porous La0.2Sr0.8Fe0.8Ta0.2O3-δ
Wibe, Petter (Master thesis, 2012)Ceramics with mixed ionic and electronic conductivity are being investigated for oxygen separation from air, intended for the production of syngas. Asymmetric membranes, consisting of a dense membrane co-sintered with a ... -
Oxygen Non-Stoichiometry and Electrical Conductivity of La0.2Sr0.8Fe0.8B0.2O3 − δ, B = Fe, Ti, Ta
Lohne, Ørjan Fossmark; Phung, Tan Nhut; Grande, Tor; Bouwmeester, Henny J. M.; Hendriksen, Peter Vang; Søgaard, Martin; Wiik, Kjell (Journal article; Peer reviewed, 2014)The oxygen non-stoichiometry was determined by coulometric titration for the perovskite oxides La0.2Sr0.8FeO3 − δ and La0.2Sr0.8Fe0.8B0.2O3 − δ (B = Ti4 + and Ta5 +) in the temperature range 600 °C ⩽ T ⩽ 900 °C and the ... -
Oxygen permeation in symmetric and asymmetric La0.2Sr0.8Fe0.8Ta0.2O3-d membranes
Gurauskis, Jonas; Lohne, Ørjan Fossmark; Lagergren, Dan Stræte; Tjønneland Wefring, Espen; Wiik, Kjell (Journal article; Peer reviewed, 2016)La0.2Sr0.8Fe0.8Ta0.2O3 − δ (LSFT) is a mixed ionic electronic conductor (MIEC) at elevated temperatures and as such a candidate material for applications both in syn-gas synthesis and as electrodes in solid oxide fuel cells ... -
Performance of a thermoelectric module based on n-type (La0.12Sr0.88)0.95TiO3-δ and p-type Ca3Co4-xO9+δ
Kanas, Nikola; Skomedal, Gunstein; Desissa, Temesgen D.; Feldhoff, Armin; Grande, Tor; Wiik, Kjell; Einarsrud, Mari-Ann (Journal article; Peer reviewed, 2020)Here, we present the performance of a thermoelectric (TE) module consisting of n-type (La0.12Sr0.88)0.95TiO3 and p-type Ca3Co4-xO9+δ materials. The main challenge in this investigation was operation of TE module in different ... -
Performance Study of MXene/Carbon Nanotube Composites for Current Collector- and Binder-Free Mg-S Batteries
Kaland, Henning; Fagerli, Frode Håskjold; Hadler-Jacobsen, Jacob; Zhao-Karger, Zhirong; Fichtner, Maximilian; Wiik, Kjell; Wagner, Nils Peter (Peer reviewed; Journal article, 2021)The realization of sustainable and cheap Mg-S batteries depends on significant improvements in cycling stability. Building on the immense research on cathode optimization from Li-S batteries, for the first time a beneficial ... -
Permeation and Mechanical Properties of Porous Supports Intended for Asymmetric Membranes Based on La(0.2)Sr(0.8)Fe(0.8)Al(0.2)O(3-δ)
Lagergren, Dan Stræte (Master thesis, 2012)Production of asymmetric ceramic membranes intended for oxygen gas separation was done by producing porous supports made from coarse La(0.2)Sr(0.8)Fe(0.8)Al(0.2)O(3-d) powder produced by the solid state reaction method. ... -
Permeation and Stability Properties of Asymmetric and Disk Shaped Oxygen Permeable Membranes Intended for Syn-Gas Production
Wagner, Nils (Master thesis, 2012)In this study, the oxygen permeation and stability properties of disk shaped and asymmetric membranes, both of the composition La0.2Sr0.8Fe0.8Al0.2O3-δ were investigated. Strontium doped Lanthanum ferrite is an oxygen ... -
pH-dependence of chloride binding in ordinary Portland cement
Hemstad, Petter (Master thesis, 2018)A new method for artificially leaching hydrated cement paste and studying how lowered pH in the pore solution affects chloride binding has been developed. Hydrated cement paste was exposed to a NaCl-solution before being ... -
Phase relations and thermomechanical properties of (Gd2Zr2O7)1-x(YbSZ)x based thermal barrier coatings (0 ≤x≤ 0.98)
Tabeshfar, Mohadese; Salehi, Mehdi; Dini, Ghasem; He, Jianying; Einarsrud, Mari-Ann; Wiik, Kjell (Peer reviewed; Journal article, 2021)Doped Gd2Zr2O7 materials have interesting properties as thermal barrier coatings (TBC) to replace the YSZ topcoats traditionally used. Here we investigate the thermomechanical properties and phase relations of Gd2Zr2O7 ... -
Processing of thin film ceramic membranes for oxygen separation
Gurauskis, Jonas; Lohne, Ørjan Fossmark; Lein, Hilde Lea; Wiik, Kjell (Journal article; Peer reviewed, 2012)Processing of dense and thin ceramic membrane layers for high temperature selective oxygen separation is addressed in this study. Mixed oxygen-ionic and electronic conducting perovskite oxide system based on La0.2Sr0.8Fe ... -
Production of Lead-free Electroceramics: K0.5Na0.5NbO3 substituted with Li & Ta
Strand, Jon Martinsen (Master thesis, 2011)K0:485Na0:485Li0:03Nb0:8Ta0:2O3 powder has been prepared by spray pyrolysis ofaqueous solutions of K/Na/Li nitrates mixed with water soluble Nb and Ta precursors.The as-prepared ceramic powder was calcined at 600 °C to ... -
Pursuing New Cathode Materials for Rechargeable Magnesium Batteries
Kaland, Henning (Doctoral theses at NTNU;2021:65, Doctoral thesis, 2021)High-performance and safe batteries based on cheap and sustainable materials are highly desirable to accelerate the transition to a renewable energy-based society. The ongoing electrification of the transport sector has ... -
Removing fluoride-terminations from multilayered V2CTx MXene by gas hydrolyzation
Fagerli, Frode Håskjold; Wang, Zhaohui; Grande, Tor; Kaland, Henning; Selbach, Sverre Magnus; Wagner, Nils Peter; Wiik, Kjell (Peer reviewed; Journal article, 2022)Two-dimensional MXenes have shown great promise for many different applications, but in order to fully utilize their potential, control of their termination groups is essential. Here we demonstrate hydrolyzation with a ... -
Self-propagating high-temperature synthesis of zirconium disilicide
Dalene, Johan Moan (Master thesis, 2020)I denne oppgaven ble en selv-utviklet reaktor som benyttet en Mg-BaO2 antennelsesblanding i en rørovn bruk til SHS av ZrSi2. Litteratur om forbrenningssyntese, zirkonium, silisium og Zr-Si systemet ble studert for å etablere ... -
Silicon for silicon nitride based products
Øvregård, Harald (Master thesis, 2013)Previous studies have shown that the oxide layer on the surface of silicon particles can reduce the hydrogen evolution that comes from contacting silicon with water during slip casting, prior to nitridation. This study ... -
Silicon for silicon nitride based products
Hem, Erik Riber (Master thesis, 2014)Previous studies have investigated the effect of the oxide layer (Ovregård 2013) and iron content (Hem 2013) on the nitridation of silicon powders. This report will take a closer look into the growth mechanisms of different ... -
Silicon for silicon nitride based products
Ovregård, Harald (Master thesis, 2013)Previous studies have shown that the oxide layer on the surface of silicon particles can reduce the hydrogen evolution that comes from contacting silicon with water during slip casting, prior to nitridation. This study ...