The development of alnico began in 1931 , when T. Mishima in Japan discovered that an alloy of iron , nickel , and aluminum had a coercivity of 400 oersted ( Oe ; 32 kA\/m ) , double that of the best magnet steels of the time .
The development of Alnico began when T Mishima in Japan found that an alloy of iron , nickel , and aluminium had double the coercivity than best magnets of that time .