Hans Schmid

Hans Schmid, Professor Emeritus of Chemistry at the University of Geneva, passed away on April 2nd 2015 in his 84th year.

Hans Schmid was born on January 11, 1931 in Reichenberg (Liberec) in the then German speaking part of the present Czech Republic. Because of the expulsion of German speakers from Czechoslovakia near the end of World War II, Hans and his family moved to Innsbruck, Austria, as passengers on a munitions train. The train was targeted for elimination by the Allies but fortunately the attempt failed. In spite of the difficulties of being a refugee, Hans flourished in his adoptive country, studying at the University of Technology at Graz. Here he received his doctoral degree in inorganic physical chemistry in 1955. Soon after he moved to the Battelle Research Laboratories in Geneva. This is where he laid the groundwork of his scientific legacy, working on the synthesis and physical properties of ferroelectric and ferroelastic materials. This research culminated in 1964 in the synthesis of single crystals of the boracite Ni₃B₇O₁₃I, the first material that was found to be simultaneously ferroelectric, (weakly) ferromagnetic and ferroelastic. Together with his long-time collaborator, Edgar Ascher, he showed that in this boracite the spontaneous electric polarization can be switched by a magnetic field and the spontaneous magnetization by an electric field. Now, 50 years later, such rigid cross-control is the Holy Grail of studies on the magnetoelectric effect. Hans presents a very lively account of this discovery in [1 ]; our favorite anecdote is that Hans had considerable trouble obtaining funding for this research as it was considered to be “too technologically motivated”. Perhaps more importantly for Hans, the move to Geneva led to his meeting Anne-Catherine, who he married in 1961 and continued to cherish, together with their four children and many grandchildren, throughout his life.

In 1977 Hans moved to the University of Geneva, first as associate then as full professor of Inorganic Applied Chemistry, Solid State Chemistry and Materials Science. With Jean-Pierre Rivera, he established one of the leading laboratories for the study of the magnetoelectric effect and the optical properties of crystals, which he directed until his retirement in 1996. In Geneva, Hans continued to make important contributions to the field of magnetoelectrics, including most importantly developing a comprehensive symmetry-based classification of ferroics and their coupling effects and introducing the concept of ferrotoroidicity as a new type of ferroic order.

He also shaped the field internationally, by founding the still continuing series of international conferences on “Magnetoelectric Interaction Phenomena in Crystals” (MEIPIC) in Seattle (1973). MEIPIC II, held in Ascona in 1993, set the stage for the subsequent Cambrian Explosion in the evolution of magnetoelectrics research. This is reflected in the conference proceedings, which, carefully composed by Hans, still make a fascinating read. In Ascona, Hans coined the term “multiferroic” to describe crystals that show at least two of the three properties ferroelectric, ferromagnetic and ferroelastic [2 ].

MEIPIC II also brought me (Fiebig) to the field of multiferroics: One of its participants travelled straight from Ascona to the University of Dortmund, Germany, where I had just begun to work on my PhD. Stimulated by the wealth of exciting novel ideas discussed in Ascona, the plan to do laser spectroscopy on Cr₂O₃, the magnetoelectric par excellence, came up. Its consequences continue to keep me busy so that Hans Schmid had set the course of my research life years before I actually met him for the first time in 1998.

My (Spaldin) first meeting with Hans occurred when I invited him to the inaugural APS meeting session on Multiferroics, appropriately in Seattle, in 2001. The boundless energy in the then rapidly burgeoning field seduced Hans happily (we hope) out of retirement and he once again made important contributions particularly in furthering understanding of the multiferroic properties of BiFeO₃ and LiMPO₄ (M = Fe, Co. Ni). Other memorable personal interactions include the fifth MEIPIC meeting in Crimea, Ukraine where we saw evidence of Hans’ long-standing efforts in scientific diplomacy. The active collaborations and friendships that he had maintained with Soviet researchers throughout the Cold War harmonize nicely with his adopted Swiss nationality. And Hans’ graceful humanity – influenced, he reminded us, by his having already enjoyed 70 bonus years since his almost fateful train journey – deeply touched the attendees at the 2012 European School on Multiferroics, which we organized as an anniversary celebration in Ascona towards the end of his life.

On hearing in 2010 that we would move to his beloved adopted Switzerland to establish Chairs in Theoretical and Experimental Multiferroics, Hans demonstrated his characteristic gentlemanly affection by quoting William Wordsworth

Doubtless his scientific legacy will continue its enthusiastic dance for many years to come.

Nicola Spaldin and Manfred Fiebig, ETH Zürich

[1] H. Schmid, “The Dice-Stone, der Würfelstein: Some personal souvenirs around the discovery of the first ferromagnetic ferroelectric”, Ferroelectrics 427 (2012) 1-33.

[2] H. Schmid, “Multi-ferroic magnetoelectrics”, Ferroelectrics 162 (1994) 317-338.