Anisotropy of ESR parameters in organic ferromagnet TDAE-C60

摘要: Abstract We study the anisotropy of ESR parameters using single crystal TDAE-C 60 , which has two polymorphisms: one is ferromagnetic a-phase and other non-ferromagnetic α′-phase. In both α′- α-phase, line-widths g-factors show anisotropic angular dependences at room temperature, such as ΔH pp b  > ΔH c  ∼ ΔH a g  > g  = g . The behaviour in phases suggest uniaxial rotation Jahn-Teller distorted C molecules around c-axis, close-packing direction molecules. α′-phase temperature dependence clear anomaly 160 K. Below this observed are in-between monovalent TDAE + indicating restoration missing spins. continuously shift with decreasing become below 230 K, no remarkable structural phase transition temperature. These results that difference exists mixing between wave functions TDAE, possibly developed by α-phases. This separates magnetic peculiarities polymorphisms