16 research outputs found
A three-dimensional temperature field calculation for a transformer-type heating element
Lead Isotope Characteristics of the Mindyak Gold Deposit, Southern Urals: Evidence for the Source of Metals
Late Cretaceous-Cenozoic history of the Lake Baikal depression and formation of its unique biodiversity
Postfire Succession of Mire Ecosystems Reconstructed Using Paleoecological Analysis: A Case Study of Novoaleksandrovskoe Mire (Meshchera Lowland, Ryazan Oblast)
Cooperative Jahn-Teller effect in a 2D mesoscopic C
Fullerene molecules adsorbed on surfaces often show macroscopic average distortions. As
charged ions C60n- are known to be Jahn-Teller (JT)
active, it is suggested that these distortions could be a manifestation of cooperative JT
effects (CJTE) due to interactions between neighbouring fullerene ions. In order to
understand the distortion properties it is necessary to take correlations between
different distortions into account. However, this canât easily be done in the mean field
approximation usually used to describe the CJTE. We therefore propose an alternative
procedure to describe 2D mesoscopic islands of C60 ions in which a pseudo
vector spin \hbox{} is evoked to represent degenerate JT-distorted states when the quadratic
JT coupling is considered. This approach is analogous to methods used for 2D magnetic
systems. We then use the differential operator technique in effective field theory within
the Ising approach. We include the effects of weak surface interactions and dynamic motion
between equivalent distortions via terms equivalent to anisotropy and a transverse field
in magnetism respectively. For distortions to
D5d symmetry, we determine single site
correlations as a function of temperature, the macroscopic average distortion describing a
structural phase transition, and the isothermal response function. Phase diagrams are
presented for relevant cases of the system parameters