He investigated the special case of a linear chain of magnetic moments, which are only able to take two positions, "up" and "down," and which are coupled by interactions between nearest neighbors.
Mainly through following studies by Rudolf Peierls, Hendrik Kramers, Gregory Wannier and Lars Onsager the model proved to be successful explaining phase transitions between ferromagnetic and paramagnetic states.
[5][6] After earning his doctorate, Ernst Ising worked for a short time in business before becoming a teacher, in Salem, Strausberg and Crossen, among other places.
Ernst and his wife Dr. Johanna Ising, née Ehmer, lived in Caputh near the famous summer residence of the Einstein family.
After the German Wehrmacht occupied Luxembourg, Ernst Ising was forced to work for the army.
On the basis of this result, he incorrectly concluded that his model does not exhibit phase transition in any dimension.
It was only in 1949 that Ising knew the importance his model attained in scientific literature, 25 years after his Ph.D. thesis.
Today, each year, about 800 papers are published that use the model to address problems in such diverse fields as neural networks, protein folding, biological membranes and social behavior.
[5][9] The Ising model had significance as a historical step towards recurrent neural networks.