2018 Annual Report of the IUCr Commission on Magnetic Structures
After the turnover of a large proportion of the membership of the commission at the IUCr Congress in Hyderabad in August 2017 (see below the present membership), in accordance with its terms of reference, the commission has continued its activities during 2018, promoting the investigation of magnetic structures as a part of crystallographic science, developing standards, encouraging their inclusion in new software, and disseminating their use, so that the research and communication of magnetic structures can reach a level of rigor and standardization similar to that achieved for ordinary structures.
The magCIF working group actively discussed a variety of revisions to the standard magCIF dictionary that was developed in previous years. To be mentioned: (1) Improvement of the descriptions of tags related to magnetic moments and incommensurate magnetic modulations. (2) Addition of a tag for the magnitude of a magnetic moment. (3) Creation of a new category for rotational moments (applicable to the pivot points of rigid units) that is highly analogous to that for magnetic moments. (4) Progress on categories for magnetic reflection data from diffraction experiments. (5) Debate on the possible addition of origin-referenced modulation parameters, as an alternative of the atom-referenced ones, which are currently used in the superspace formalism.
Also within this area of development of extended CIF standards for the communication of magnetic structures, we have started to work on the so-called smCIF dictionary for the description of magnetic and other symmetry-lowered crystal structures in terms of symmetry-modes (basis functions of matrix representations of the parent symmetry group). This smCIF dictionary is a most needed addition to the magCIF standard, which will allow to standardize the communication of magnetic structures when described using the so-called representation method, and most importantly, when both representation analysis and magnetic symmetry groups are considered together, which in the most general case is the most efficient and complete approach to the description of a magnetic structure. A first draft of the smCIF dictionary, including some examples has been proposed by the commission chair Branton Campbell, and has been first discussed by an ad-hoc working group of interested people among the membership and the consultants of the commission. In accordance with our terms of reference, these CIF related activities have been done in close contact with the chair of the COMCIFS commission, James Hester.
Another task has been the preparation of the Erice school, “Magnetic crystallography”, sponsored by the IUCr and organized by the commission, which will take place in June 2019. The organization of this school has run smoothly but has required an important amount of time and effort on the part of Branton Campbell, Maria Teresa Fernandez and J. Manuel Perez Mato, acting as directors of the school, and with the fundamental collaboration of Annalisa Guerri and Paola Spadon, executive secretary and treasurer, of the Erice crystallography schools. Successive steps in the organization have been completed in 2018: programme design, lecturers selection and invitation, announcement distribution, funding raising, school schedule design, registration of participants, evaluation and screening of applications, etc. About 100 applications were received, and due to the constraints on the school size, only 65 participants could be selected. Many of the selected participants are young scientists from developing countries, who will receive some kind of bursary support. 17 presenters will deliver the lectures and practical tutorials of the school. Among them, all members of the commission will participate, but other people responsible of some of the latest developments in methods, software and techniques will also be present. Our intention is that the school becomes a window showing the present state of the art of magnetic structure determination, and a benchmark that will encourage further developments and progress in the methods and software tools available for the analysis of magnetic structures.
The members of the commission have also continued working on the promotion of the visibility of the research on magnetic structures in the annual meetings of the IUCr Regional Associates. Our aim is that this very specific research community is well represented within these meetings. Since a few years, it has been achieved that all the annual ECA meetings include a specific session on magnetic structure research, and the 2018 Oviedo meeting has maintained this feature, which we hope will tend towards permanence. Commission secretary J.M. Perez-Mato was one of the invited speakers of this session in Oviedo, and used the opportunity to promote the advantages of analysing and communicating incommensurate magnetic structures using the superspace group formalism, which is the method used in the magCIF dictionary.
The commission supports a variety of scientific meetings each year through formal sponsorship, and with its members and consultants participating in featured lecture presentations, workshop tutorials, organization and chairing of conference sessions, and the presentation of lecture courses. Highlights from 2018 include the following:
- American Crystallographic Association Meeting, 20-24 July 2018, Toronto Canada. Session on Theoretical and Computational Crystallography – Present and Future Opportunities at the Structural Interface of Experiment and Theory (Co-chair: Branton Campbell).
- Aperiodic 2018 – 9th conference on Aperiodic Materials,Ames, Iowa, USA, 8-13 July , 2018 (invited talk: M. Henriques).
- Workshop at ISIS Neutron and Muon Source – Rutherford Appleton Laboratory,Didcot, Oxford, UK, 11-13 April, 2018, ‘Jana2006 for crystal and magnetic structure determination from TOF neutron data’ (lectures and tutorials: M. Henriques).
- Workshop on single crystal neutron diffraction, ‘The magnetic option of Jana2006’, included in the IKON15 (In-Kind Contributions Meeting for Neutron Science for Instruments), Lund, Sweden, 10-14 September, 2018 (lectures and tutorials: M. Henriques).
- 7th School on Representational Analysis and Magnetic Structures (RAMS), University of Maryland, USA, June 19-22, 2018 (organization: O. Garlea, lectures and tutorials: B. Campbell, A. Wills, O. Garlea).
- Workshop on Symmetry-mode analysis of magnetic and displacive structures, Oak Ridge National Laboratory, USA Aug 15-16, 2018 (organizer: O. Garlea, lectures and tutorials: B. Campbell).
- International Conference on Magnetism (ICM 2018), San Francisco, USA, July 15 – 20, 2018 (talk: O. Garlea).
- European Crystallographic Meeting, ECM31, Oviedo, Spain, August 22-27, 2018 (MS invited talk: J.M. Perez-Mato).
- China Institute of Atomic Energy, Beijing, 19 December, 2018 (seminar and tutorial: Max Avdeev).
- XVII International Small Angle Scattering Conference (SAS2018), Oct. 7-12, 2018, Grand Traverse City, USA (invited plenary talk: T.J. Sato).
- 22nd workshop on quasicrystals, Tohoku University, Sendai, Japan, Mar. 5-6, 2018 (T.J. Sato).
- Tutorial workshop for magnetic materials, Kanda, Tokyo, Japan, Nov. 11, 2018 (T.J. Sato).
- Programme Committee in the Magnetic structure section of International research conference of using neutron scattering on condensed matters NSCM, St. Petersburg Russia, 17 – 21 Sep. 2018 (member: A. Pirogov).
- 6th International Conference on Superconductivity and Magnetism, Antalya, Turkey, Apr. 24- May. 4, 2018 (sessions chair: J. Campo).
- International Conference on Magnetism, San Francisco, USA, july 15-19, 2018 (session chair: J. Campo).
- 43rd International Conference on Coordination Chemistry (ICCC2018), Sendai, Japan,, july 30, aug. 4, 2018 (invited talk: J. Campo).
Commission membership: Branton Campbell (Chair, USA), Maxim Avdeev (Australia), Maria Teresa Fernandez-Diaz (France), Ovidiu Garlea (USA), Margarida Henriques (Czech Republic), J. Manuel Perez-Mato (Spain), Juan Rodriguez-Carvajal (France), Taku Sato (Japan), Andrew Wills (UK), and Oksana Zaharko (Switzerland).
Commission consultants: Mois Aroyo (Spain), J. Campo (Spain), Danny Litvin (USA), Alexander Pirogov (Russia) and Wieslawa Sikora (Poland).