Zoe Barber
Reader
MA University of Cambridge
PhD University of Cambridge
+44 (0)1223 334326
zb10@cam.ac.uk
www.msm.cam.ac.uk/dmg/
Thin Film Deposition
My research interests are based around thin-film deposition using a range of techniques: magnetron sputtering, ionized sputter deposition, pulsed-laser ablation and sol-gel fabrication. Within the Device Materials Group we are developing and optimizing the growth of many different thin-film device materials, which may be amorphous, polycrystalline or single crystal. These include magnetic alloys and compounds, ferroelectrics, dielectrics, superconductors, multiferroics, as well as tunnel barriers, buffer layers, contacts and encapsulation layers.
In relation to a wider range of thin-film applications we are investigating ultra-hard coatings (e.g. nano-composites, epitaxial nitride multilayers); biomedical coatings (e.g. doped hydroxyapatite); shape-memory metals and precise free-standing structures for nanotechnology applications; and multilayers for X-ray mirrors and for studies of interdiffusion.
Film growth techniques are being developed to further improve the control of film structure (e.g. ion-enhanced deposition), and we are using optical emission spectroscopy and plasma probes for detailed diagnostics of the film growth environment.
Spintronics
In order to optimise spin dependent transport between ferromagnetic metals and semiconductors we are developing methods for the deposition of ferromagnetic electrodes on insulating tunnel barriers on semiconductors. This requires careful preparation of the semiconductor surface using in-situ surface cleaning techniques in an ultra-high vacuum deposition system.
Superconducting junctions
Measurement of the spectrum of quantum fluctuations in niobium-nitride-based superconducting tunnel junctions may answer questions about the source of dark energy in the universe. We are developing and optimising the fabrication of very high critical current density, shunted NbN junctions for this application.
- XB Hu, A Garg & ZH Barber, "Deposition and characterization of pulsed-laser-deposited and chemical-solution-derived Sm-substituted bismuth titanate films" Integrated Ferroelectrics 79, 113–121 (2006).
- LJ Singh, CW Leung, C Bell, JL Prieto & ZH Barber, "Magnetoresistance of spin valve structures based on the full Heusler alloy Co2MnSi" J. Appl. Phys. 100, 013910 (2006).
- ES Thian, J Huang, ME Vickers, SM Best, ZH Barber & W Bonfield, “Silicon-substituted hydroxyapatite (SiHA): A novel calcium phosphate coating for biomedical applications” J. Mater. Sci. 41, 709–717 (2006).
- S Sanjabi, SK Sadrnezhaad & ZH Barber, “Sputter alloying of Ni, Ti and Hf for fabrication of high temperature shape memory thin films” Mater. Sci. Technol. 23, 987–991 (2007).
- MA Moram, Y Zhang, MJ Kappers, ZH Barber & CJ Humphreys “Dislocation reduction in gallium nitride films using scandium nitride interlayers” Appl. Phys. Lett.91, 152101 (2007).