https://www.royalsociety.org.…

Digby D. Macdonald, a pioneering scientist in corrosion and electrochemistry, passed away in June 11th, 2025 at the age of 81.

Born December 7, 1943, in Thames, New Zealand, to Leslie Graham and Francis Helena (Verry) Macdonald. Digby earned his bachelor’s and master’s degrees at the University of Auckland, then completed a Ph.D. in Chemistry at the University of Calgary, Canada.

He was remembered for his groundbreaking research, mentorship, and distinguished academic career across several leading universities. Remembered not only for his scientific achievements but also for his mentorship of students and colleagues worldwide. His work continues to influence nuclear engineering, materials science, and corrosion research. Remembered not only for his scientific achievements but also for his mentorship of students and colleagues worldwide. His work continues to influence nuclear engineering, materials science, and corrosion research. His contributions remain foundational in the field of corrosion science, and his passing is a significant loss to the global scientific community. Tributes emphasize that his mentorship and kindness extended beyond his professional circle into his family life, where he was remembered as a devoted husband, father, grandfather, and brother.

He was married to Mirna Urquidi-Macdonald. Mirna was Digby’s longtime partner and spouse, supporting him through his distinguished academic career in corrosion science and electrochemistry. 

Mirna,

From the group in Paris and myself in remembrance of all the scientific and much more exchanges we had in so many occasions with him and Mirna

Michel

Prof. Macdonald was an incredible person whose deep passion for science and dedication to nurturing the next generation of scientists left an indelible mark on many lives, including mine. He gave me the life-changing opportunity to join his team, which changed the course of my life and had a lasting positive impact on my family.

In 2016, I received an offer from Digby to join his group as a researcher. To say I was happy would be an understatement. I simply couldn’t believe such an opportunity was real. For two years, I had the chance to learn about electrochemistry and corrosion from the very best!

I will never forget how Digby and Mirna welcomed me with such kindness, offering me a place to stay in their home when I first arrived in California. When Digby and Mirna greeted me at the airport with open arms, I felt a deep sense of kinship that has stayed with me forever.

Digby helped me become the scientist I am today. His mentorship, brilliance, and generosity shaped not only my career, but my identity as a person. He was a monumental figure in corrosion and, just as importantly, a man with a heart full of love. 

Thank you for everything, Digby. You will always be remembered and profoundly missed.

I was always excited whenever I received a message or phone call from Prof. Macdonald. But on June 11, I saw a message from him on my phone—at first, I felt that familiar excitement, until I opened it. The news of his passing was one of the saddest messages I have ever received.

I first reached out to Prof. Macdonald in 2010, when I was a master’s student in Iran, seeking his insights on impedance spectroscopy. He generously and graciously offered his time to answer my many questions, held video calls with me on Skype, revised my manuscripts, and later wrote numerous recommendation letters for my Ph.D. applications to universities across Europe, New Zealand, Australia, and the United States. He even personally contacted professors to help me find a research group. Thanks to his support, I was accepted as a research scholar at the University of Wisconsin–Madison in 2016.

Finally, after seven years of communicating through email and video calls, I had the honor of meeting him in person when he and Prof. Mirna visited UW-Madison in the fall of 2017. It was one of the most memorable moments of my life.

During my Ph.D. at Lehigh University (2019–2023), Prof. Macdonald served as my co-advisor and a member of my dissertation committee while he was a professor-in-residence at UC Berkeley. In my research, I applied his Point Defect Model to investigate the mechanism of anodic gold oxide formation—a project that has since received meaningful attention. He personally trained me in the use of his model over more than a decade of discussions and thousands of emails. His mentorship was profound and irreplaceable.

I am forever grateful for Prof. Macdonald’s unwavering support, mentorship, and extraordinary kindness. He profoundly shaped both my academic career and my personal growth. I’ve tried to summarize our 15-year friendship and mentorship in just a few paragraphs, but words can hardly capture the depth of his impact.

My heartfelt condolences go out to his beloved wife, Prof. Mirna Urquidi-Macdonald, and to the rest of his family. May you find comfort in knowing how deeply he was admired and how far his influence reached. I miss him dearly and will always carry his memory with deep respect and gratitude.

Prof. Digby was not only a brilliant scientist in corrosion, but also one of the kindest and most patient people I’ve ever met. He spent hours helping me with my experiments and papers, always encouraging and thoughtful. He was truly the best mentor I’ve ever had.

Thanks to the opportunity he gave me, I was able to come to the U.S., where I met my husband. Now we have a happy family with a son and a daughter — something I will always be grateful for.

It was an honor to know him. He made a big difference in my life.

He will be deeply missed.

ALUMNUS OBITUAR Reporoa College 

Digby Macdonald PhD Chemistry and Nobel Prize nominee in Chemistry. Reporoa College student in the late 1950's and previously a Reporoa Primary student. His mother was also a past teacher of the College.

Professor Macdonald passed away on June 12th. A hugely accomplished gentleman who while living abroad was still proud of his New Zealand heritage,

Following is an exert from The Third International Online Conference on Corrosion and Materials Degradation explaining the vastness of Professor Macdonald's accomplishments

--------

Digby was appointed Professor of Residence in the Departments of Materials Science and Engineering and Nuclear Engineering at University of California, Berkeley in 2012. His appointment at Berkeley was preceded by a Professorship in MSE at the Ohio State University and a Distinguished Professorship in MSE at Pennsylvania State University (PSU). In addition to his academic career Digby held a number of technical management positions including Director of the Center for Advanced Materials and Director of the Center for Electrochemical Science and Technology, as well as Chair of the Metals Program at PSU. From 1984 to 1991 he held consecutive appointments as Laboratory Director of the Chemistry Laboratory and of the Materials Research Laboratory, and Deputy Director of the Physical Sciences Division at SRI International, where he also served as Vice President for two years.

Professor Macdonald was a prolific and productive researcher who consistently made insightful and innovative contributions on a range of topics related to the electrochemical behavior of metals, ceramics and polymers, especially as regard their use in the generation, transport and storage of energy. Digby was unique in his ability to conduct high quality, insightful experiments and to develop predictive models based on fundamental principles. He was equally at home as an experimentalist and as a theoretician.

Professor Macdonald’s research has had an enormous impact on our understanding of the passive films responsible for the behavior of corrosion resistant metals and alloys. Versions of his Point Defect Model have been widely used in the nuclear power industry and has been applied to predict the long-term performance of critical structural materials including stainless steels and Nickel-Chromium base alloys in commercial nuclear reactors.

Professor Macdonald’s research in corrosion, the development of reference electrodes, which are essential for electrochemical studies, and his investigations of the fundamental aspects of electrochemical reactions taking place at various battery electrodes were furthered by his employment of electrochemical impedance spectroscopy. Digby developed innovative kinetic models to interpret the impedance spectra and pioneered the use of Kramers-Kronig Transforms to establish the validity of measured electrochemical impedance spectra. Of his many hundreds of publications, the ones he most enjoyed preparing were those he co-authored with his wife, Professor Mirna Uquidi-Macdonald

From Arthur Motta, June 16, 2025

The recent passing last weekend of Digby Macdonald has moved me to write a short

recollection of him. Digby was brilliant; he could dazzle you with it and leave you

wanting more. I first met him when I was hired at Penn State in 1992. Digby had just

moved to Penn State MatSE from SRI International the year before. Because we had a

common interest in material for nuclear power, we decided to meet to see if we could

collaborate. I went to his office in Steidle Bldg and we talked a couple hours about

corrosion, stress corrosion cracking and what proposals to write for the Nuclear

Regulatory Commission. At the end of that time, he took out a yellow pad and started to

write a proposal in perfect cursive, with hardly any words crossed out for 4-5 pages,

without stopping. When he put his pen down, we had a fully written proposal. I was

amazed and a little afraid “is that what every Penn State professor can do? If so, can I

even measure up??...”. The fact we did not get funded that time is almost incidental.

I do recall another occasion in which he impressed in a different way. In August 1995 we

were both in Breckenridge Colorado, for a conference on Corrosion. The organizers put

together a Quick Draw Contest for the participants, as if we were gunfighters in the Old

West. Digby would be a very unlikely candidate to get a quick draw – he was pretty far

from the most athletic person you could ever imagine- but… damned if he did not win

the whole contest (!) Of all the attendees he had the quickest draw of a gun from his

waist..

Digby became one of my mentors, we co-advised my first grad student and we

eventually taught a course together, NucE/MatSE523 “Environmental Degradation of

Materials in Nuclear Power Plants”. Of the course it could have been said that it was

“East is East, and West is West, and never the twain shall meet”: Digby talked about

electrochemistry and corrosion potential, and I talked about radiation damage, and

material microstructure. However, I do recall vividly the impression he made on me in

one of his lectures. He talked for one whole hour, without notes or interruption, about

water and its properties, and it was completely fascinating, although for the life of me I

could not tell you now what he specifically said. The only comparison I can make is

when I was listening to Richard Feynman talk, saying yes, yes, and after the talk I could

not remember what he actually said…

Digby was certainly not Feynman, and had his blind spots which he was completely

unable to notice, but this could have been his strength: he was always optimistic and

convinced he was going to a better place in science, as in life. I do hope this is where

he now is.

Arthur Motta, June 16, 2025