Room temperature ferromagnetism in Teflon due to carbon dangling bonds

Abstract

The ferromagnetism in many carbon nanostructures is attributed to carbon dangling bonds or vacancies. This provides opportunities to develop new functional materials, such as molecular and polymeric ferromagnets and organic spintronic materials, without magnetic elements (for example, 3d and 4f metals). Here we report the observation of room temperature ferromagnetism in Teflon tape (polytetrafluoroethylene) subjected to simple mechanical stretching, cutting or heating. First-principles calculations indicate that the room temperature ferromagnetism originates from carbon dangling bonds and strong ferromagnetic coupling between them. Room temperature ferromagnetism has also been successfully realized in another polymer, polyethylene, through cutting and stretching. our findings suggest that ferromagnetism due to networks of carbon dangling bonds can arise in polymers and carbon-based molecular materials.

Substitution Boosts Charge Separation for High Solar-Driven Photocatalytic Performance

“…22 Defects, as active sites where the charge carriers can be effectively separated, 23,24 have been recently reported to narrow the band gap as well. 25 Thus, the defect bismuth oxy-hybrid-halides have the potential to reconcile the apparent contradiction between bandgap narrowing and performance, and to provide an ideal platform to attain a comprehensive understanding of correlations between the structure, defects, and properties.…”

d° Ferromagnetism of Magnesium Oxide

“…Vacancy mediated magnetism occurs in CuO [17] and ZnO [18,19]; oxygen vacancy induced magnetism in zinc peroxide [20] and CeO 2 [21]; and surface vacancy induced magnetism in NiO [22]. Thus, these studies reveal that defects in the form of vacancies are the source of this behavior [11][12][13][14][15][16][17][18][19][20][21][22], however, sustainability of this magnetism up to long-range order requires exigency of the mechanism of interaction among these sources. It was observed that this kind of magnetism is governed by the double exchange mechanism through p-p interactions in Mg-doped SnO 2 [23], as well as B-, C-, and N-doped BeO systems [24].…”

“…To date, this magnetism is observed in a variety of materials with different sources of origin and is classified accordingly [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”

“…Carbon dangling bonds/vacancies are responsible for RTFM in polymers and carbon-based molecular materials [12][13][14]. RTFM in Ca-and Mg-stabilized zirconia is ascribed to oxygen vacancies [15].…”

Surprising attraction of non-magnetic materials to magnets

“…Earlier civilizations relied on this force to create devices such as compasses [2]. Magnetism is now broadly studied in many realms and with many materials, particularly with regard to practical applications [3][4][5][6][7].…”