No abstract

First ESR studies are reported on oriented carbynoid samples prepared by chemical dehydrofluorination of poly(vinylidene fluoride) films. Two types of paramagnetic centres (PC), denoted as C-M1 and C-M2, and an anisotropic broad line were detected. The spectra of the PC C-M1 are isotropic with a g-value of . The absorption by given PC is well saturated at room temperature and the PC C-M1 can be attributed either to free radical states or pinned quasi-particles similar to topological Su-Schrieffer-Heeger solitons. The ESR and microwave photoconductivity results obtained confirm the quasi-1D nature of the carbon chains, being the structural elements of the samples studied, and agree with the assumption that the ground state of carbon chains is a state with a spin density wave (SDW) realized at room temperature. The ESR spectrum of the PC C-M2 consisting of a series of unsaturated lines is anisotropic both in relation to the static magnetic field and in relation to the magnetic component of the microwave field. The study of the interaction dynamics of the microwave field with PC C-M2, the absorption dependence with increase of the microwave field and the temperature dependence allow us to attribute the PC C-M2 to mobile quasi-particles, being domain walls in the alternated spin density distribution, tentatively solitons in the SDW. It has been found that spin waves associated with the PC C-M2 can be observed in samples treated thermally at for 2 hours (the samples contained fluorine with atomic ratio F/C = 3/7 and oxygen at 20 at.%). It has been proven that the spin waves' excitation and the formation of quasi-particles like solitons can represent the same process.

No abstract

No abstract

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.