Dr Julian Dean
School of Chemical, Materials and Biological Engineering
Senior Lecturer in Materials Science
Head of First year (MSE UG)
j.dean@sheffield.ac.uk
+44 114 222 5473
+44 114 222 5473
Sir Robert Hadfield Building
Full contact details
Dr Julian Dean
School of Chemical, Materials and Biological Engineering
Sir Robert Hadfield Building
Mappin Street
Sheffield
S1 3JD
School of Chemical, Materials and Biological Engineering
Sir Robert Hadfield Building
Mappin Street
Sheffield
S1 3JD
- Profile
-
I obtained my Masters in Physics (MPhys) from the University of Sheffield in 2004. My PhD award in 2007 on micro-electromechanical systems looked at the incorporation of magnetostriction in magMEMS. I subsequently worked as a Research Associate in the Department of Science and Engineering Materials, where I was made a University Teacher in 2011, lecturer in 2013, and Senior lecturer in 2015.
- Research interests
-
The study of functional materials and their responses - design, characteristaion and optimisation.
This includes:
- The development of a finite element modelling techniques to understand how materials respond from external stimuli.
- Multi-physics finite element simulations combining, electrical, thermal and structural analysis.
Key projects:
- Development of magnetic materials for motor and drives (working with VW)
- Development of dielectric mateirals for capactiors (working with KAVX)
- Development of local impedance Spectroscopy techniques to characterise materials for fusion technologies. (working with UKAEA)
- Publications
-
Journal articles
- Modifications to the spreading resistance equation when using micro-contact impedance spectroscopy to measure resistive surface layers.. Solid State Ionics, 414, 116652-116652.
- Influence of electrode contact arrangements on Polarisation-Electric field measurements of ferroelectric ceramics: A case study of BaTiO3. Journal of Materiomics, 100939-100939.
- A total rip-off—crack propagation in paper. Physics Education, 59(3), 035010-035010.
- A finite element study on the influence of surface cracks on micro-contact impedance spectroscopy measurements. Solid State Ionics, 393, 116173-116173.
- Induced internal stresses and their relation to FLASH sintering of KNN ceramics. Journal of Materials Chemistry C, 10(30), 10916-10925.
- Bending bad—testing caramel wafer bars (#TestATunnocks). Physics Education, 56(5), 055002-055002.
- Anomalous grain boundary conduction in BiScO3-BaTiO3 high temperature dielectrics. Acta Materialia, 117136-117136.
- Resource efficient exploration of ternary phase space to develop multi-layer ceramic capacitors. Acta Materialia, 207, 116690-116690.
- Front Cover: The Role of Particle Contact in Densification of FLASH Sintered Potassium Sodium Niobate (Eur. J. Inorg. Chem. 39/2020). European Journal of Inorganic Chemistry, 2020(39), 3708-3708.
- The role of particle contact in densification of FLASH sintered potassium sodium niobate. European Journal of Inorganic Chemistry. View this article in WRRO
- Finite element modeling of resistive surface layers by micro‐contact impedance spectroscopy. Journal of the American Ceramic Society, 103(4), 2702-2714. View this article in WRRO
- Modelling the particle contact influence on the Joule heating and temperature distribution during FLASH sintering. Journal of the European Ceramic Society. View this article in WRRO
- Mechanism of densification in low-temperature FLASH sintered lead free Potassium Sodium Niobate (KNN) piezoelectrics. Journal of Materials Chemistry C. View this article in WRRO
- The analysis of impedance spectra for core–shell microstructures : why a multiformalism approach is essential. Advanced Functional Materials, 29(38). View this article in WRRO
- Three-dimensional virtual microstructure generation of porous polycrystalline ceramics. Ceramics International. View this article in WRRO
- Optimizing size and distribution of voids in phenolic resins through the choice of catalyst types. Journal of Applied Polymer Science. View this article in WRRO
- Predicting the energy storage density in poly(methyl methacrylate)/methyl ammonium lead iodide composites. Journal of Applied Physics, 125(21). View this article in WRRO
- High quality factor cold sintered Li2MoO4BaFe12O19 composites for microwave applications. Acta Materialia, 166, 202-207. View this article in WRRO
- Material and magnetic properties of Sm2(Co, Fe, Cu, Zr)17 permanent magnets processed by Spark Plasma Sintering. Journal of Alloys and Compounds, 770, 765-770. View this article in WRRO
- Modeling the Influence of Two Terminal Electrode Contact Geometry and Sample Dimensions in Electro-materials. Journal of the American Ceramic Society. View this article in WRRO
- Complexities of atomic structure at CdO/MgO and CdO/Al 2O 3 interfaces. Journal of Applied Physics, 124(20). View this article in WRRO
- Electric field enhancement in ceramic capacitors due to interface amplitude roughness. Journal of the European Ceramic Society. View this article in WRRO
- Morphology characterisation of inclusions to predict the breakdown strength in electro-ceramic materials: Microstructure modelling. Ceramics International. View this article in WRRO
- Improved breakdown strength and energy storage density of a Ce doped strontium titanate core by silica shell coating. Journal of Materials Chemistry C, 6(34), 9130-9139. View this article in WRRO
- Prismatic core high temperature reactor fuel modelling incorporating fuel rotation. Nuclear Engineering and Design, 331, 153-161. View this article in WRRO
- Finite element modeling on the effect of intra-granular porosity on the dielectric properties of BaTiO₃ MLCCs. Journal of the American Ceramic Society, 101(3), 1211-1220. View this article in WRRO
- How to extract reliable core-volume fractions from core-shell polycrystalline microstructures using cross sectional TEM micrographs. Journal of the European Ceramic Society, 37(8), 2795-2801. View this article in WRRO
- Design of a bilayer ceramic capacitor with low temperature coefficient of capacitance. Applied Physics Letters, 109. View this article in WRRO
- A sweeter way of teaching health and safety. Physics Education, 51(5), 053006-053006. View this article in WRRO
- Carbon uptake and distribution in Spark Plasma Sintering (SPS) processed Sm(Co, Fe, Cu, Zr)z. Materials Letters, 171, 14-17. View this article in WRRO
- A resource efficient design strategy to optimise the temperature coefficient of capacitance of BaTiO3-based ceramics using finite element modelling. Journal of Materials Chemistry A, 4(18), 6896-6901. View this article in WRRO
- A sound idea: Manipulating domain walls in magnetic nanowires using surface acoustic waves. Applied Physics Letters, 107(14). View this article in WRRO
- Simulation of Impedance Spectra for Core-Shell Grain Structures Using Finite Element Modeling. Journal of the American Ceramic Society, 98(6), 1925-1931. View this article in WRRO
- From compass to hard drive—integrated activities for studying magnets. Physics Education, 49(6), 663-670.
- Simulation of impedance spectra for a full three-dimensional ceramic microstructure using a finite element model. Journal of the American Ceramic Society, 97(3), 885-891. View this article in WRRO
- Influence of thermal energy on exchange-bias studied by finite-element simulations. APPLIED PHYSICS LETTERS, 103(4).
- High-performance composite chocolate. Physics Education, 48(4), 465-471.
- Dynamics of stress-induced domain wall motion. PHYSICAL REVIEW B, 85(14).
- Transverse and vortex domain wall structure in magnetic nanowires with uniaxial in-plane anisotropy.. J Phys Condens Matter, 24(2), 024205. View this article in WRRO
- Head and bit patterned media optimization at areal densities of 2.5 Tbit/in2 and beyond. Journal of Magnetism and Magnetic Materials, 324(3), 269-275.
- The formation mechanism of 360 degrees domain walls in exchange-biased polycrystalline ferromagnetic films. J APPL PHYS, 110(7).
- Numerical study of the effective magnetocrystalline anisotropy and magnetostriction in polycrystalline FeGa films. J APPL PHYS, 110(4).
- Nanowire spintronics for storage class memories and logic.. Philos Trans A Math Phys Eng Sci, 369(1948), 3214-3228.
- Exchange-bias in amorphous ferromagnetic and polycrystalline antiferromagnetic bilayers: Structural study and micromagnetic modeling. J APPL PHYS, 109(8).
- Stress-based control of magnetic nanowire domain walls in artificial multiferroic systems. Journal of Applied Physics, 109(2).
- The incorporation of the Cauchy stress matrix tensor in micromagnetic simulations. J APPL PHYS, 108(7).
- Influence of oscillation modes on the line width of rf emissions in MgO based nanopillars. J MOL CATAL A-CHEM, 328(1-2).
- Comparison of Exchange-Bias Using Epitaxial and Polycrystalline Ir0.2Mn0.8 Antiferromagnetic Thin Films: a TEM and Lorentz TEM Study. Microscopy and Microanalysis, 16(S2), 1914-1915.
- The effect of trapping superparamagnetic beads on domain wall motion (vol 96, 192503, 2010). APPL PHYS LETT, 96(23).
- The effect of trapping superparamagnetic beads on domain wall motion. APPL PHYS LETT, 96(19). View this article in WRRO
- Kronecker product approximation of demagnetizing tensors for micromagnetics. J COMPUT PHYS, 229(7), 2544-2549.
- Exchange bias interactions in polycrystalline/amorphous bilayers. APPL PHYS LETT, 96(7).
- The role of local anisotropy profiles at grain boundaries on the coercivity of Nd
2 Fe14 B magnets. Applied Physics Letters, 97(23).
- Head and bit patterned media optimization at areal densities of 2.5 Tbit/in2 and beyond. Journal of Magnetism and Magnetic Materials.
- Increases in effective head field gradients in exchange spring media. APPL PHYS LETT, 95(17).
- Tailoring Domain-Wall Dynamics With Uniaxial Anisotropy in Nanowires. IEEE TRANSACTIONS ON MAGNETICS, 45(10), 4067-4069.
- Exchange Coupled Bit Patterned Media Under the Influence of RF-Field Pulses. IEEE TRANSACTIONS ON MAGNETICS, 45(10), 3851-3854.
- A study of hard:soft layer ratios and angular switching in exchange coupled media. J APPL PHYS, 106(5).
- Microwave-assisted three-dimensional multilayer magnetic recording. APPL PHYS LETT, 94(23).
- Micromagnetics of single and double point contact spin torque oscillators. J APPL PHYS, 105(8).
- Internal effective field sources for spin torque nanopillar oscillators. J APPL PHYS, 105(5).
- Bringing science research into secondary schools. Physics Education, 44(6), 627-632.
- Mutual phase locking in high-frequency microwave nano-oscillators as a function of field angle. J MAGN MAGN MATER, 320(17), L111-L115.
- Thermally induced adjacent track erasure in exchange spring media. APPL PHYS LETT, 92(14).
- Micromagnetic calculation of spin wave propagation for magnetologic devices. JOURNAL OF APPLIED PHYSICS, 103(7).
- Recording simulations on graded media for area densities of up to 1 Tbit/in.(2). APPL PHYS LETT, 91(22).
- Finite-element analysis on cantilever beams coated with magnetostrictive material. IEEE T MAGN, 42(2), 283-288. View this article in WRRO
- Finite element modelling of a magnetostrictive coated cantilever system as a function of magnetic film thickness. INTERMAG 2006 - IEEE International Magnetics Conference, 598.
- Application of Johnson's approximation in finite element modeling for electric field‐dependent materials. International Journal of Applied Ceramic Technology.
- Using metadynamics to obtain the free energy landscape
for cation diffusion in functional ceramics : dopant
distribution control in rare earth-doped BaTiO3. Advanced Functional Materials. View this article in WRRO
- From insulator to oxide-ion conductor by a synergistic effect from defect chemistry and microstructure: acceptor-doped Bi-excess sodium bismuth titanate Na0.5Bi0.51TiO3.015. Journal of Materials Chemistry A.
Conference proceedings papers
- Finite element study of the effect of particle interaction on the energy storage density of composite dielectrics. Energy Procedia, Vol. 151 (pp 129-134), 11 September 2018 - 12 September 2018. View this article in WRRO
- Reversal Mechanism of Exchange-Biased CoFeB/IrMn Bilayers Observed by Lorentz Electron Microscopy. IEEE TRANSACTIONS ON MAGNETICS, Vol. 45(10) (pp 3873-3876)
- Microwave-Assisted Magnetization Reversal in Exchange Spring Media. IEEE TRANSACTIONS ON MAGNETICS, Vol. 44(11) (pp 3519-3522)
- Finite element/boundary element simulation of future hard disk recording. COMPUTATIONAL METHODS AND APPLIED COMPUTING (pp 430-435)
Preprints
- Finite Element Modelling of Impedance Spectroscopy Data in Composite
Electroceramics.
- Modifications to the spreading resistance equation when using micro-contact impedance spectroscopy to measure resistive surface layers.. Solid State Ionics, 414, 116652-116652.
- Teaching activities
-
Head of 1st year (MSE)
MAT109 - Skills for engineers (1st year module)
MAT1643 / AER11004 - mechanical properites of materials (1st year module)
MAT2350 - Artefacts project (2nd year module)
MAT3281 - Finite element modelling (3rd year module)
Julian is actively involved in public outreach and education, particularly with school age students. Working with Dr Dan Allwood and Dr Matthew Bryan, he assisted local Sixth Form students in conducting research on designing new magnetic hard drive materials. This work resulted in a research paper [J. Appl. Phys. 106, (2009) 053902] and an education paper on the project itself [Phys. Ed. 44 (2009) 627]. Julian was also co-awarded the 2009 Kroto Prize for Excellence in the Science Education of Young People.
He has run hands-on Materials outreach activities for school students from 5 – 18. These sessions include ‘High-performance composite chocolate’ (Ages 5-21) [Phys. Ed 48 2013] , ‘Magnets’ (Ages 7-11) and ‘Structural materials properties’ (Ages 14-18). Most recently worked with Dr Dan Allwood to develop a suite of Flash-based virtual experiments to support Physics A-level tuition: FlashyScience. These have been used to deliver lessons to A-level (16-18 years) students and are used as part of graduate programmes.