Influence of defects on the critical behaviour at the \boldmath{105} K structural phase transition of SrTiO$_3$: I. The broad component

Details Influence of defects on the critical behaviour at the \boldmath{105} K structural phase transition of SrTiO$_3$: I. The broad component Influence of defects on the critical behaviour at the \boldmath{105} K structural phase transition of SrTiO$_3$: I. The broad component

2000-06-08

arxiv.org/abs/cond-mat/0006127v2

Physics

Condensed Matter

Materials Science

16 pages, 6 figures. submitted to Phys. Rev. B

Scientific paper

The critical fluctuations in SrTiO$_3$ near its $105 K$ structural phase transition were studied with triple axis diffractometry using high energy ($\ge 100 keV$) synchrotron radiation in different SrTiO$_3$ crystals with different oxygen vacancy concentrations. Due to the presence of oxygen vacancies the critical behaviour is changed compared to defect-free systems. In our experiments a smearing out of the squared order parameter and a crossover of the critical exponents $\nu$ and $\gamma$ above the phase transition temperature is observed, with the crossover temperature strongly depending on the concentration of the defects. To understand the experimental findings, e.g. the unusual values for the critical exponents found near the critical temperature, the Ginzburg-Landau-Wilson functional for structural phase transitions in disordered systems was analyzed using renormalization group theory and the replica trick. Considering the effects of defects which locally increase the transition temperature leads to a qualitative understanding of the observed behaviour. The crossover behaviour of the critical exponents can be modeled and a quantitative analysis of the observed experimental data is presented.

Affiliated with

Also associated with

No associations

Rating

Influence of defects on the critical behaviour at the \boldmath{105} K structural phase transition of SrTiO$_3$: I. The broad component does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Influence of defects on the critical behaviour at the \boldmath{105} K structural phase transition of SrTiO$_3$: I. The broad component, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Influence of defects on the critical behaviour at the \boldmath{105} K structural phase transition of SrTiO$_3$: I. The broad component will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-407199