We are still mourning the passing away from our friend Larry Kaufman. I was thinking about him today, thinking about how lucky I was to have the opportunity to know him in person and thought about other friends, some who already left us, and some who are still with us. I decided to choose three of them, to share with you some of my recollections of the interaction with these extraordinary persons. This is no biography, I just want to share few memories which are special to me.
The first one, of course, must be Larry (Lawrence) Kaufman. I first heard his name as co-autor (with Berstein) of a book called CALPHAD, which we (still) have in our library. I first met him in Erice, at the 1996 Calphad conference in Italy, He knew I worked in the MPI Eisenforschung so he called me aside, to show a calculation of Al-Ti-Fe phase diagram using his database (which uses only crude models, regular solutions, ideal solutions, line compounds), showing he could reproduce a particularly tricky phase equilibriium involving the t2 phase, my colleagues had experimentally determined. This was characteristic from him. It does not matter that he coined the term CALPHAD, that in some sense, he was a kind o "father" to us all, he was always available and interacting, even with the humblest of the graduate students (myself). It in not everyday that you have the opportunity to "chat" with the person who created an entire scientific discipline (computational thermodynamics) and a whole industry (e.g. Thermo-calc, Pandat and so on).
The second extraordinary person is John Cahn (to my best knowledge, still alive and well). I met him at many occasions, but I remind in particular, my visit to NIST in 2001 on the way to the CALPHAD in Boston. I was showing some results on modelling crystal defects in intermetallics and said that I was doing that for my "Livre-docência" thesis (some Brazilian copy of the German habilitation). He told me he, in his entire life, had written only one thesis, his Ph. D. . The implication was clear. If he, himself, needed only a title, why should anyone else have other titles? I realized this and quickly answered that by doing this, I would get a 30% raise in my salary and he replied then, therefore, that I should do it, laughing. John Cahn is well known, even to physicist, due to the Hilliard-Cahn equation and some consider that he is the closest materials science will ever get to a Nobel prize winner.
The third special person was Ryioichi Kikuchi. One of the most privileged minds I ever met, I consider him to be of the level of Einstein, Bohr, Heisenberg and Feynman. I was working at the MPI Eisenforschung in Düsseldorf and met this tiny japanese guy walking in the corridor. I knew already he was coming for a three months for the fourth round of the Alexander von Humbolt prize grant, so I guessed right. At that time I remember him telling me his first recollection of Brazil was about watching one of his relatives departing on a ship to a distant country which was painted in green at the Mapa Mundi he had in his fundamental school. I made that time the decision to invite him to visit Brazil, so he could have opportunity to visit this lost branch of his family, what we did in year 2000. Sadly he passed away 10 years ago, but his memory will stay with me forever.