Introduction

As in past years, the science produced in the general area of X-ray absorption and magnetic scattering covers a very wide range of subjects. The growing trends are the combination of techniques, the extension of existing methods to new applications and the development of new X-ray methods. For example, the X-ray Detected Magnetic Resonance (XDMR) article – (Goulon et al.).

There are also examples of measurements on the femtosecond time scale using the core-hole clock method (Braicovich et al.) and on femtometre length scale in magnetostriction measurements (Pettifer et al.). Magnetic circular dichroism methods have been used as an indirect probe to study quantum diffusion (Ohresser et al.) and coherent diffraction has been utilised to study charge density wave dislocations (Le Bolloch et al.). Many of the studies in the following pages push the limits of methods utilising high pressure, high magnetic fields, high and low temperature with absorption or scattering techniques to expand our knowledge in many fields (Acet et al., Mannix et al., Poloni et al., Wilkins et al.). More will surely be forthcoming in the near future with facilities like the 10T magnet reaching its full potential on ID20 and the further exploitation of the XDMR technique on ID12. The impact of this later work could easily be very wide and some experiments have also been made in this general direction in the soft X-ray range [1].

Growing trends also include the use of novel in situ preparation techniques, an example of which is the in situ plasma treatment of samples (Farle et al.). In addition, the combination of many spectroscopic methods to address a single problem is becoming increasingly important, particularly in chemistry, as shown by the study on “metal organic frameworks” (Prestipino et al.). Also X-ray absorption studies have been used to address difficult biological problems such as the oxidation state of copper in complexes (D’Angelo et al.).

It should also be mentioned that there are many other noteworthy studies which could not be included. For example, work published in the past year has shown that additional information can be extracted by measuring the spin polarisation of emitted electrons. One paper explored the pure Fano effect in ferromagnets with an important theoretical aspect to the understanding of the phenomena [2]. Another study combined X-ray absorption measurements at the NSRRC source in Taiwan and spin polarised measurements at the ESRF to investigate the problem of orbital liquids by studying the orbital moment and crystal field splitting in LaTiO3 [3]. Again one sees that by being able to measure another experimental observable more information can be gained.

In summary, the research highlights of the past year show an evolution of the research into new and potentially very exciting directions. Old methods are being used for new problems, additional insight is being obtained by the combination of methods and new experimental tools are being developed. These trends are important today and for the future as we will see in future highlights.

N. Brookes

 

References

[1] Boero et al. Appl. Phys. Lett. 87, 152503 (2005).
[2] Minar et al. Phys. Rev. Lett. 95, 166401 (2005).
[3] Haverkort et al. Phys. Rev. Lett. 94, 056401 (2005).