Julian Walker
Kjemi 2, 122, Gløshaugen, Sem Sælands vei 12
About
Julian Walker is an Associate Professor at the Department of Materials Science and Engineering in the Functional Materials and Materials Chemistry research group (FACET). Julian is a materials scientist with expertise in the synthesis and characterization of inorganic and hybrid ferroic materials. Currently his core interest is developing hybrid ionic plastic crystal systems as novel phase change and ferroic materials. In these systems the interplay of different external stimuli such as temperature, electric field, stress or magnetic field cna be utilized to augment the phase transition parameters or for the purposes of electromechancial coupling and charge storage.
Background
Julian obtained his PhD from the University of New South Wales, Australia in 2014, in the group of Prof. Nagarajan Valanoor. He was then a postdoctoral researcher at the Electronic Ceramics Department, Jozef Stefan Institute, Slovenia with Prof. Barbara Malic for two years. Later Julian joined the Materials Research Institute, Pennsylvania State University where he spent two and a half years in the group of Prof. Susan Trolier-McKinstry working with piezoelectric thin film application and innovation, with projects like the development of piezoelectric adjustable optics as a candidate technology for NASA's proposed Lynx telescope.
Teaching
Julian is currently the course responsible and main lecturer for TMT4145 Ceramic Engineering and TMT4245 Functional Materials masters and undergraduate level courses in the Depatment of Materials Science and Engineering.
Research Areas
- Fundamental composition, structure and property relationships in ferroelectrics
- Engineering of plastic crystal ferroics
- Piezoelectric thin films for specialized MEMS applications
- Lead-free ferroelectrics and multiferroics
- In situ and advanced electromechanical characterization techniques
- Sustainable electronics
- Phase change materials for thermal energy storage
Honors/Awards
- Excellence in Reviewing, Scripta Materiala, 2018
- Outstanding Reviewer, Journal of Materials Chemistry C, 2018
- Best Young Researcher award, Piezoresponse Force Microscopy and Nano-scale Phenomena in Polar Materials conference, 2014
- Australian Postgraduate Award - Industry, University of New South Wales, Australia, 2010-2013
Competencies
Publications
2022
- Nylund, Inger-Emma; Løndal, Nora Statle; Walker, Julian; Vullum, Per Erik; Einarsrud, Mari-Ann; Grande, Tor. (2022) Cation Disorder in Ferroelectric Ba4M2Nb10O30 (M = Na, K, and Rb)Tetragonal Tungsten Bronzes. Inorganic Chemistry. volum 61 (39).
- Walker, Julian; Marshall, Kenneth Paul; Beceiro, Jorge Salgado; Williamson, Benjamin; Løndal, Nora Statle; Castro-Garcia, Socorro; Andújar, Manuel Sánchez; Selbach, Sverre Magnus; Chernyshov, Dmitry; Einarsrud, Mari-Ann. (2022) Mesophase Transitions in [(C<inf>2</inf>H<inf>5</inf>)<inf>4</inf>N][FeBrCl<inf>3</inf>] and [(CH<inf>3</inf>)<inf>4</inf>N][FeBrCl<inf>3</inf>] Ferroic Plastic Crystals. Chemistry of Materials. volum 34 (6).
2021
- Denis-Rotella, Lyndsey M.; Esteves, Giovanni; Walker, Julian; Zhou, Hanhan; Jones, Jacob L.; Trolier-Mckinstry, Susan. (2021) Residual Stress and Ferroelastic Domain Reorientation in Declamped {001} Pb(Zr0.3Ti0.7)O3 Films. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. volum 68 (2).
2020
- Liu, Lisha; Rojac, Tadej; Kimpton, Justin; Walker, Julian; Makarovic, Maja; Li, Jing-Feng; Daniels, John E.. (2020) Poling-induced inverse time-dependent microstrain mechanisms and post-poling relaxation in bismuth ferrite. Applied Physics Letters. volum 116 (12).
- Walker, Julian; Miranti, Rany; Skjærvø, Susanne Linn; Rojac, Tadej; Grande, Tor; Einarsrud, Mari-Ann. (2020) Super-coercive electric field hysteresis in ferroelectric plastic crystal tetramethylammonium bromotrichloroferrate(III). Journal of Materials Chemistry C. volum 8 (9).
- Walker, Julian; Mirjanic, Anja; Sadl, Uros; Condurache, Oana Andreea; Bencan, Andreja; Rojac, Tadej; Grigoras, Marian; Uršič, Hana. (2020) Magnetic contributions in multiferroic gadolinium modified bismuth ferrite ceramics. Scripta Materialia. volum 188.
- Walker, Julian; Scherrer, Simon Wolfgang; Løndal, Nora Statle; Grande, Tor; Einarsrud, Mari-Ann. (2020) Electric field dependent polarization switching of tetramethylammonium bromotrichloroferrite(III) ferroelectric plastic crystals. Applied Physics Letters. volum 116 (24).
2019
- Cardoletti, Juliette; Radetinac, Aldin; Thiem, Daniel; Walker, Julian; Komissinskiy, Philipp; Xu, Bai-Xiang; Schlaak, Helmut; Trolier-Mckinstry, Susan E; Alff, Lambert. (2019) Modelling of the vertical deflection of ferroelectric bending tongues loaded at their free end. AIP Advances. volum 9 (2).
- Coleman, K; Walker, Julian; Beechem, Thomas E; Trolier-Mckinstry, Susan E. (2019) Effect of stresses on the dielectric and piezoelectric properties of Pb(Zr0.52Ti0.48)O3 thin films. Journal of Applied Physics. volum 126 (3).
- Ibn-Mohammed, Taofeeq; Randall, Clive A; Mustapha, Khameel B; Guo, Jing; Walker, Julian; Berbano, Seth; Koh, SC Lenny; Wang, Dawei; Sinclair, Derek C; Reaney, Ian Michael. (2019) Decarbonising ceramic manufacturing: A techno-economic analysis of energy efficient sintering technologies in the functional materials sector. Journal of the European Ceramic Society. volum 39 (16).
- Makarovic, M; Bencan, A; Walker, Julian; Malic, B; Rojac, T. (2019) Processing, piezoelectric and ferroelectric properties of (x)BiFeO3-(1-x)SrTiO3 ceramics. Journal of the European Ceramic Society. volum 39 (13).
Journal publications
- Nylund, Inger-Emma; Løndal, Nora Statle; Walker, Julian; Vullum, Per Erik; Einarsrud, Mari-Ann; Grande, Tor. (2022) Cation Disorder in Ferroelectric Ba4M2Nb10O30 (M = Na, K, and Rb)Tetragonal Tungsten Bronzes. Inorganic Chemistry. volum 61 (39).
- Walker, Julian; Marshall, Kenneth Paul; Beceiro, Jorge Salgado; Williamson, Benjamin; Løndal, Nora Statle; Castro-Garcia, Socorro; Andújar, Manuel Sánchez; Selbach, Sverre Magnus; Chernyshov, Dmitry; Einarsrud, Mari-Ann. (2022) Mesophase Transitions in [(C<inf>2</inf>H<inf>5</inf>)<inf>4</inf>N][FeBrCl<inf>3</inf>] and [(CH<inf>3</inf>)<inf>4</inf>N][FeBrCl<inf>3</inf>] Ferroic Plastic Crystals. Chemistry of Materials. volum 34 (6).
- Denis-Rotella, Lyndsey M.; Esteves, Giovanni; Walker, Julian; Zhou, Hanhan; Jones, Jacob L.; Trolier-Mckinstry, Susan. (2021) Residual Stress and Ferroelastic Domain Reorientation in Declamped {001} Pb(Zr0.3Ti0.7)O3 Films. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. volum 68 (2).
- Liu, Lisha; Rojac, Tadej; Kimpton, Justin; Walker, Julian; Makarovic, Maja; Li, Jing-Feng; Daniels, John E.. (2020) Poling-induced inverse time-dependent microstrain mechanisms and post-poling relaxation in bismuth ferrite. Applied Physics Letters. volum 116 (12).
- Walker, Julian; Miranti, Rany; Skjærvø, Susanne Linn; Rojac, Tadej; Grande, Tor; Einarsrud, Mari-Ann. (2020) Super-coercive electric field hysteresis in ferroelectric plastic crystal tetramethylammonium bromotrichloroferrate(III). Journal of Materials Chemistry C. volum 8 (9).
- Walker, Julian; Mirjanic, Anja; Sadl, Uros; Condurache, Oana Andreea; Bencan, Andreja; Rojac, Tadej; Grigoras, Marian; Uršič, Hana. (2020) Magnetic contributions in multiferroic gadolinium modified bismuth ferrite ceramics. Scripta Materialia. volum 188.
- Walker, Julian; Scherrer, Simon Wolfgang; Løndal, Nora Statle; Grande, Tor; Einarsrud, Mari-Ann. (2020) Electric field dependent polarization switching of tetramethylammonium bromotrichloroferrite(III) ferroelectric plastic crystals. Applied Physics Letters. volum 116 (24).
- Cardoletti, Juliette; Radetinac, Aldin; Thiem, Daniel; Walker, Julian; Komissinskiy, Philipp; Xu, Bai-Xiang; Schlaak, Helmut; Trolier-Mckinstry, Susan E; Alff, Lambert. (2019) Modelling of the vertical deflection of ferroelectric bending tongues loaded at their free end. AIP Advances. volum 9 (2).
- Coleman, K; Walker, Julian; Beechem, Thomas E; Trolier-Mckinstry, Susan E. (2019) Effect of stresses on the dielectric and piezoelectric properties of Pb(Zr0.52Ti0.48)O3 thin films. Journal of Applied Physics. volum 126 (3).
- Ibn-Mohammed, Taofeeq; Randall, Clive A; Mustapha, Khameel B; Guo, Jing; Walker, Julian; Berbano, Seth; Koh, SC Lenny; Wang, Dawei; Sinclair, Derek C; Reaney, Ian Michael. (2019) Decarbonising ceramic manufacturing: A techno-economic analysis of energy efficient sintering technologies in the functional materials sector. Journal of the European Ceramic Society. volum 39 (16).
- Makarovic, M; Bencan, A; Walker, Julian; Malic, B; Rojac, T. (2019) Processing, piezoelectric and ferroelectric properties of (x)BiFeO3-(1-x)SrTiO3 ceramics. Journal of the European Ceramic Society. volum 39 (13).