21. Ferromagnetism occurs when individual atoms are paramagnetic and the spin vectors are aligned parallel to each other in a crystalline material.22. Unlike ferromagnetism , anti-ferromagnetic interactions can lead to multiple optimal states ( ground states states of minimal energy ). 23. He used X-rays to investigate ferromagnetism , concluding that it was a result of the alignment of electron spins. 24. They give rise to ferromagnetism , antiferromagnetism or ferrimagnetism, depending on the nature and relative orientations of the individual spins. 25. Anti-ferromagnetism is another example of a magnetic property arising from a particular alignment of individual spins in the solid state. 26. Low-defect graphene nanomeshes manufactured by using a non-lithographic method exhibit large-amplitude ferromagnetism even at room temperature. 27. Ferromagnetism is a property not just of the chemical make-up of a material, but of its crystalline structure and microstructure.28. In order to have ferromagnetism , the atoms must have permanent magnetic moments which are not due to the motion of classical charges. 29. Paramagnetism is not a collective phenomenon, which means that the ferromagnetism of the macrostate was not conserved by going into the nanostate. 30. Hideo Ohno and his group at the Tohoku University were the first to measure ferromagnetism in transition metal p-type charge carriers.
