Institute for Materials Research, Tohoku University, the Birthplace of
Physical Metallurgy and Magnetism Research in Japan and Its Collection
of Historical Materials in Honda Memorial Hall

The Institute for Materials Research at Tohoku University (formerly the Second Department of the Provisional RIKEN Institute) was founded by Kotaro Honda. In contrast to the empirical and phenomenological metallurgy of the time, Honda introduced “Physical Metallurgy” to Japan, incorporating microscopic physical perspectives—such as magnetic analysis and structural observation—into experimental research.In 1916, Honda and Hiroshi Takagi invented “KS magnet steel,” the world’s first artificially synthesized permanent magnet. This invention was a groundbreaking achievement that dramatically improved magnetic properties through controlled composition of an iron alloy containing cobalt, tungsten, and chromium, and it garnered widespread attention at the time as the world’s strongest permanent magnet.

From the perspective of “metallurgical physics,” a significant achievement in the physics of materials was the experimental demonstration of “crystalline magnetic anisotropy” in iron and other materials by Honda and Seiji Kaya in 1926. Through precise experimental studies using single crystals, they were the first in the world to clarify the dependence of magnetization on the crystal orientation in ferromagnetic materials.This pioneering achievement has become a timeless milestone, still featured in textbooks on solid-state physics and magnetic physics today.This empirically grounded academic foundation paved the way for subsequent developments, ranging from the invention of “Sendust,” a soft magnetic material with high magnetic permeability (1932, Ryo Masumoto, Institute for Metal Research, Tohoku University), to samarium-cobalt magnets (early 1970s, Yoshio Tawara, Ph.D. in Science, Tohoku University, 1967),to neodymium magnets (1982, Masato Sagawa, Ph.D. in Engineering, Tohoku University [Institute of Metal Research], 1972)—a series of developments that established Japan as a global leader in the high-performance magnets that underpin modern society. These physical inquiries and empirically grounded research on diverse substances and materials have produced numerous talented individuals throughout Japan (the Honda School).

In addition, the structure of the former Building No. 1—built entirely of red brick and concrete without any reinforcing bars for the purpose of magnetic research—as well as the meticulous experimental notebooks from that era by Honda and his colleagues, the “Kinken Method,”and the wooden three-dimensional model of the three-component magnetic susceptibility phase diagram for Sendast—which emerged from the meticulous experiments known as “Honda-ism”—convey to this day the research ethos of that era, characterized by a thorough exploration of materials and a pursuit of precise experimental measurements.Guided by the philosophy that “Industry is the training ground for academia,” this property—which demonstrates a history of directly linking the pursuit of physical truths to applications in metallurgy and making significant contributions to Japan’s science, technology, and industry—possesses the value worthy of designation as a “ Japan Physics Heritage.”

Open to the public and currently on display. Among these, the collection of experimental notebooks by Kotaro Honda and others is available for viewing upon request.