Professor of Physics
Department: Physics & Astronomy
Appointments: Professor, Frontier Institute for Research in Sensor Technologies
Address: 5708 ESRB-Barrows Hall, Room 265
- 1980 B.S., Northwestern University
- 1986 Ph.D., Cornell University
- Surface and Interface Properties of Materials
- Synthesis and Processing of Ceramic and Semiconducting Thin Films
- Electronic Properties of Materials;
- Thin Film Sensor Materials
- Metal-Ceramic and Ceramic-Ceramic Interfaces
- Defects in Materials
- Scanning Probe Microscopy
- X-ray Diffraction
- Tribology of Hard Coatings
- Reactivity and Degradation of Ceramic Surfaces and Films
- Chemical Gas Sensors
- High Temperature Materials
- Harsh Environment Sensors
Prof. Lad has been at the University of Maine since 1988, and is a member of the Laboratory for Surface Science & Technology (LASST), an interdisciplinary research center at UMaine that focuses on surfaces, interfaces, thin films, micro-devices, and nanotechnology. He has been the PI or Co-PI on 42 grants totaling over $40 million from agencies including NSF, ONR, DARPA, DOE, NASA, AFOSR, AFRL, ARO, and several industries, to support his research programs. He and his students have authored 115 journal publications and given over 200 presentations at scientific meetings. He has advised individual research projects for 7 postdocs, 15 Ph.D., 6 M.S., and 63 undergraduate students.
His laboratory contains a versatile Thin Film Synthesis, Processing & Characterization facility that is equipped with instrumentation including several different thin film deposition techniques (e-beam, sputtering, ALD, GLAD, plasma-assisted growth), x-ray and uv photoelectron spectroscopies, electron and x-ray diffraction, scanned probe microscopies, high temperature furnaces, and a controlled-atmosphere conductivity/Hall effect apparatus.
Prof. Lad obtained a B.S. in Materials Engineering from Northwestern University in 1980, and Ph.D. in Materials Science from Cornell University in 1986 working on high temperature gaseous corrosion of metallic alloys. Prior to joining the faculty at the University of Maine, he was a Postdoctoral Associate in the Department of Applied Physics at Yale University, where he studied the surface science of metal oxides and performed photoemission studies of the electronic structure of oxide materials at the National Synchrotron Light Source. He was the Director of UMaine’s Laboratory for Surface Science & Technology (LASST) from 1996-2014, and he received the UMaine Presidential Research and Creative Achievement Award in 2004, a UMaine System Trustee Professorship in 2006, and the Distinguished Maine Professor Award in 2013.
“Distinguishing Bulk Conduction from Band Bending Transduction Mechanisms in Chemiresistive Metal Oxide Gas Sensors,” A. Reghu, L.J. LeGore, J.F. Vetelino, R.J. Lad, B.G. Frederick, J. Physical Chemistry C (2018); doi:10.1021/acs.jpcc.8b01446.
“Enhanced Crystallinity in h-BN Films Induced by Substrate Biasing During Magnetron Sputtering,” D.M. Stewart, R.J. Lad, Physica Status Solidi B 255 (2018) 1700458; doi:10.1002/pssb.201700458
“Electronic and Thermal Properties of Stoichiometric Pt3Si Films Grown by Co-Evaporation,” R.T. Fryer, R.J. Lad, J. Materials Science 53 (2018) 3524-3536; doi:10.1007/s10853-017-1758-2
“Zirconium Diboride Thin Films for Use in High Temperature Sensors and MEMS Devices,” D.M. Stewart, G.P. Bernhardt, R.J. Lad, Smart Sensors, Actuators, and MEMS VIII, edited by L. Fonseca, M. Prunnila, E. Peiner, Proc. of SPIE Vol. 10246, 102460Q (2017) SPIE; doi:10.1117/12.2266561.
“Stability of Pt/Al2O3-Based Electrode Langasite SAW Sensors with Al2O3 Capping Layer and Yttria-Stabilized Zirconia Sensing Layer,” A. Maskay, A. Ayes, R.J. Lad, M. Pereira da Cunha, Proc. of 2017 IEEE International Ultrasonics Symposium (2017) 1-4.
“Langasite 2.45 GHz ISM Band SAW Resonator for Harsh Environment Wireless Applications,” M. Pereira da Cunha, A, Maskay, R.J. Lad, T. Coyle, G. Harkay, Proc. of 2016 IEEE International Ultrasonics Symposium (2016) 1-4.
“Rotorcraft Turbine Engine Applications of the Environetix Wireless High Temperature Surface Acoustic Wave Micro-Electromechanical Machines Sensor System,” J. Moffatt, M. Pereira da Cunha, R.J. Lad, J. American Helicopter Society 61 (2016).
“Comparison of PtSi Films Grown by Solid-State Reaction and by E-Beam Co-Evaporation: Thermal Stability in Air at 1000°C,” R.T. Fryer, R.J. Lad, MRS Advances 1 (2016) 1539-1544.
“Electrical Conductivity and Thermal Stability of Pt3Si, Pt2Si, and PtSi Films Grown by E-beam Co-evaporation,” R.T. Fryer, R.J. Lad, J. Alloys Compounds 682 (2016) 216-224.
“Pt-Ni / Pt-Zr Electrodes for Stable SAW Resonator Operation During Repeated Temperature Cycling up to 1000ºC,” M. Pereira da Cunha, A. Maskay, R.J. Lad, D.J. Frankel, S. Moulzolf, M. Call, G. Bernhardt, Proc. of 2015 International Ultrasonics Symposium 10 (2015) 1-4; doi:10.1109/ULTSYM.2015.0028
“Influence of Composition and Multilayer Architecture on Electrical Conductivity of High Temperature Pt-Alloy Films,” D.J. Frankel, S.C. Moulzolf, M. Pereira da Cunha, R.J. Lad, Surface & Coatings Technology 284 (2015) 215-221.
“Nanostructure and Bonding of Zirconium Diboride Thin Films Studied by X-ray Spectroscopy,” D.M. Stewart, R.W. Meulenberg, R.J. Lad, Thin Solid Films 596 (2015) 155-159.
“Electrically Conductive Pt-Zr-B and Pt-Si Thin Films for Use in High Temperature Harsh Environments,” R.J. Lad, D.M. Stewart, R.T. Fryer, J.C. Sell, D.J. Frankel, G.P. Bernhardt, R.W. Meulenberg, MRS Proceedings 1746 (2015); doi:10.1557/opl.2015.400.
“Growth, Structure, and High Temperature Stability of Zirconium Diboride Thin Films,” D.M. Stewart, D.J. Frankel, R.J. Lad, J. Vac. Sci. Technol. A 33 (2015) 031505.
“Electrically Stable Nanocomposite Thin Films Formed by Oxidation of Pt-ZrB2 Nanolaminate Templates,” J.C. Sell, D.M. Stewart, G.P. Bernhardt, D.J. Frankel, R.J. Lad, J. Vac. Sci. Technol. B 33 (2015) 021805.
“Wireless Harsh Environment SAW Array System for Power Plant Application,” M. Pereira da Cunha, R.J. Lad, T.B. Pollard, D. McCann, E. McCarthy, P. Prata, R. Kelley, Proc. of 2014 International Ultrasonics Symposium 381-384 (2014).
“Influence of Dosing Sequence and Film Thickness on Structure and Resistivity of Al-ZnO Films Grown by Atomic Layer Deposition,” E.B. Pollock, R.J. Lad, J. Vac. Sci. Technol. A 32, 041516 (2014).
“Properties of Amorphous SiAlON Thin Films Grown by RF Magnetron Co-Sputtering,” G.P. Bernhardt, J.I. Krassikoff, B.T. Sturtevant, R.J. Lad, Surface & Coatings Technology 258, 1191–1195 (2014).
“High Temperature Stability of Electrically Conductive Pt-Rh/ZrO2 and Pt-Rh/HfO2 Nanocomposite Thin Film Electrodes,” S.C. Moulzolf, D.J. Frankel, M. Pereira da Cunha, R.J. Lad, Microsystems Technology 20, 523–531 (2014).
“Tetrahedrally Coordinated Disordered (Cu2SnS3)1-x(ZnS)x Alloys with Tunable Optical and Electronic Properties,” P.T. Erslev, M.R. Young, J.V. Li, S.C. Siah, R. Chakraborty, H. Du, R.J. Lad, T. Buonassisi, G. Teeter, Solar Energy Materials and Solar Cells 129, 124-131 (2014).
“Energy Conversion Efficiency of an Exponentially Graded Thermoelectric Material,” Zhi-He Jin, T.T. Wallace, R.J. Lad, Ji Su, Journal of Electronic Materials 43, 308-313 (2014).
“Wireless Battery-Free Harsh Environment Sensor System for Energy Sector Applications,” M. Pereira da Cunha, R.J. Lad, D. Frankel, S C. Moulzolf, M. Call, G. Bernhardt, D. McCann, T. Pollard, E. McCarthy, IEEE Future of Instrumentation International Workshop Proceedings (2013).
“Thin Films and Techniques for Above 1000°C SAW Sensor Operation,” R. Behanan, S.C. Moulzolf, M. Call, G. Bernhardt, D.J. Frankel, R.J. Lad, M. Pereira da Cunha, Proc. of 2013 International Ultrasonics Symposium, pp. 1013-1016 (2013).
“Capacitively Coupled IDT for High Temperature SAW Devices,” S. C. Moulzolf, R. Behanan, T. Pollard, R.J. Lad, M. Pereira da Cunha, Proc. of 2013 International Ultrasonics Symposium, pp. 255-258 (2013).
“Properties of SiAlO2N Protective Coatings on Surface Acoustic Wave Devices,” B.T. Sturtevant, M. Pereira da Cunha, R. J. Lad, Thin Solid Films 534, 198-204 (2013)
“Langasite SAW Pressure Sensor for Harsh Environments,” S.C. Moulzolf, R. Behanan, R.J. Lad, M. Pereira da Cunha, Proc. of 2012 IEEE International Ultrasonics Symposium, Dresden, Germany, pp. 1224-1227 (2012).
“Challenges in Ceramic Science: A Report from the Workshop on Emerging Research Areas in Ceramic Science,” G.S. Rohrer, R.J. Lad, et al., J. Am. Ceram. Soc. 95, 3699-3712 (2012).
“Temperature Threshold for Nanorod Structuring of Metal and Oxide Films Grown by Glancing Angle Deposition,” D. Deniz, R.J. Lad, J. Vac. Sci. Technol. A 29, 011020 (2011).
“Charge Transport in Flat and Nanorod Structured Ruthenium Thin Films,” M.M. Steeves, D. Deniz, R.J. Lad, Applied Physics Letters 96, 142103 (2010).
“Influence of Nanostructure on Charge Transport in RuO2 Thin Films,” M.M. Steeves, R.J. Lad, J. Vac. Sci. Technol. A, 28, 906 (2010).
“Nanostructured Tungsten and Tungsten Trioxide Films Prepared by Glancing Angle Deposition,” D. Deniz, D.J. Frankel, R.J. Lad, Thin Solid Films 518, 4095 (2010).
Updated July 2018