Observation of magnetic domains in graphene magnetized by controlling temperature, strain and magnetic field.

Since the production of ferromagnetic graphene as an extremely important matter in spintronics has made a revolution in future technology, a great deal of efforts has recently been done to reach a simple and cost-effective method. Up to now, controlling the magnetic properties at extremely low temperature have been investigated only by adding and removing atoms in graphene lattice. In this regard, the effect of strain on the magnetic and electronic properties of graphene has been probed. Here, the ferromagnetic properties are what have been created by strain, magnetic field, and temperature along with observation of the parallel magnetic domains in ferromagnetic graphene for the first time as a great achievement. In this way, we have represented the following: First, introducing three novel methods based on temperature, magnetic field, and strain for producing ferromagnetic graphene; Second, obtaining ferromagnetic graphene at room temperature by significant magnetization saturation in mass-scale; Third, probing the electronic systems and vibrational modes by Raman and IR spectroscopy; Fourth, introducing stacking and aggregation as two types of gathering process for graphene sheets; Fifth, comparing the results with leidenfrost effect-based method which the temperature, magnetic fields, and strain are simultaneously applied to graphene flakes (our previous work).