DUAL ACCESS

Services needed to prepare experiments in EMFL facilities are available, including magnetotransport, Scanning Tunneling Microscopy. Other probes which can be considered upon request. The UAM hosts vectorial (5+1+1) magnets as well as 17 T and a 22 T magnet. There are a number of magnets producing fields up to 12 T. The UAM hosts five functional dilution refrigerator units, reaching temperatures from 10 mK to 50 mK.

MGML offers open access to its services to users from the basic and applied research areas. Details of all the instrumental equipment, including compatible sample environment, can be found on the webpage.

The services for the measurement of material properties include magnetization, AC magnetic susceptibility, heat capacity, electrical resistivity, magnetoresistance, electrical capacity, permittivity, magnetoelectric response, Hall resistivity, thermal conductivity, Seebeck effect, thermal expansion, magnetostriction, AFM, MFM or PFM.
The suite of magnets, cryostats, and pressure cells enables to carry out these measurements in magnetic fields up to 19.5 T, in a broad temperature interval from 30 mK up to several hundred degrees Celsius, electric fields from -50V to + 50V, and hydrostatic and uniaxial pressures up to 15 GPa.
In addition, MGML offers services for synthesis and characterization of materials – metals, intermetallics, semimetals, oxides or inorganic salts. Several complementary techniques are available for crystal growth: Czochralski, Bridgman, floating-zone (mirror or laser furnace), flux-growth, chemical vapor transport, hydrothermal growth. Modern DTA/DSC analysis, scanning electron microscopes and broad range of X-ray diffraction instruments (operating in the range of 3 – 1200 K) allow detailed structural and phase characterization of samples.
The services to users are supported by a high-expertise advice and assistance of the scientific and technical MGML staff. The remote online access is possible for majority of our instruments.
MGML holds an official license for onsite manipulation of materials containing U and Th for research purposes, allowing the synthesis and measurement of materials containing these elements.

The Oxford Centre for Applied Superconductivity (CFAS) was recently set up in January 2017 based on an investment by the Local Growth Funding through Oxfordshire County Council and the Oxfordshire Local Enterprise Partnership as well as by the University of Oxford and local industrial partners working on superconductivity which includes Oxford Instruments and Siemens (~ 4.5M€).

The Centre is a Superconductivity Hub with interests in future applications of superconducting materials which aims to pursue projects that can lead to future technologies and lead to the discovery of novel superconducting materials. The Centre helps to train people with necessary skills in superconductivity which can be transferable to other relevant industries. Currently, the Centre is developing a series of experimental and testing facilities in a new purpose built laboratory equipped with a modern 16T Physical Properties Measurement System (PPMS) for testing the magnetic and transport properties of new superconducting materials and a 17T magnet and high current power supplies to test superconducting wires and tapes up to 1200 A relevant for applications in industry. This 16T PPMS is a user facility and runs 24 hours per day, 7 days per week, and it has a very large user base being used for characterization of novel superconducting and topological single crystalline samples.

The areas of research normally pursued at this facility include fundamental and critical studies of novel superconducting materials, fermiology and magnetotransport studies of new single crystalline materials. New techniques, such as applied pressure up to 30kbar and a tunnel diode oscillation system, have been recently developed for the PPMS up to 16T and down to 1.7K. These low field studies constitute an important part for the successful experiments and time allocation at high field facilities of EMFL and elsewhere.

Oxford also benefits from a large number of superconducting high magnetic fields which form a local High Magnetic Field facility with fields up to 21T and equipped with variable temperature inserts and dilution refrigerators for transport, optical and thermodynamic studies.

Oxford University hosts the Nicholas Kurti Magnetic Field Laboratory, which is a local pulsed field facility which could allow the running of three experimental magnet cells, which are powered by a configurable capacitor bank with maximum energy storage up to 3MJ. Pulsed magnets are designed and wound in-house and have achieved fields up to 50 – 60 T. Pulse lengths of the order of 10 ms can be adjusted by changing the configuration of the capacitor bank and repetition times are under an hour for full field shots. Non-standard and custom-made magnets are also available with longer pulse lengths, but typically at the cost of peak field.

The pulsed field laboratory has been recently upgraded with a new capacitor bank from 0.8MJ to 3MJ and it is in advance testing phase towards completion. A new 70T magnet has been built to be tested using the new upgraded facilities.

Experimental capabilities contain compensated coil magnetometry for the measurements of absolute magnetization in milligram samples of magnetic material. This technique is highly sensitive to magnetic phase transitions and energy level crossings. The electronic behaviour of metallic and superconducting systems can be investigated by resisitivity, skin-depth and penetration using contacted and contactless methods. Furthermore, measurements of the Fermi surface of conducting materials using de Haas-van Alphen and Shubnikov-de Haas quantum oscillation effects are possible using ³He refrigerators enable experiments to take place at temperatures down to 400 millikelvin.

The Spintronics and Nanomagnetism Laboratory is hosted within the joint laboratories among University of Salento and CNR-Institute of Nanotechnology, which represent one of the largest Nanotechnology infrastructure in Italy. Notably, the infrastructure includes also fully equipped clean room for nanofabrication and material growth, nanochemistry, photonics and biology facilities providing an ideal location for multidisciplinary and applied research for in-house and visiting researchers before translating the experiments to the largest EMFL facilities when higher magnetic fields are required. R

esearch highlights include the demonstration of sign reversal of magnetoresistance in tunnel junctions with nanocrystal superlattices and the discovery of electrostatic spin crossover in insulating molecules with super-exchange magnetic interaction and inversion symmetry breaking (with publications on high impact factor journals such as Nat. Mat., Nano Letters, ACS-Nano). Research activities and achievements are disseminated to schools, general public and (yearly) within the European Researchers’ Night. Research is funded by EU, national and regional projects.

Services currently offered

Currently, there are several returning users from EU – Budapest for THz, and Southampton for NMR. Other, rather random users include Helsinki, Turku, Stockholm, Ljubljana, Krakow, and Moscow. for PPMS Tartu and Lappenranta. The most used is the THz lab with their options, but also the cryoMAS and even static NMR has been widely used. The PPMS serves as the magnetometer for the entire northern Baltic region and is a rare option even for groups of Sweden and Finland.

As materials, mostly multi-ferroics and superconductors, but also thin ALD films of oxides and doped fullerenes have been measured and the results published.

Services currently offered

• Oxford Instruments 16.5 T superconducting magnet.
• 50 mm diameter, room temperature bore.
• Cryogenic Ltd. 18.3 T superconducting magnet.
• 58 mm diameter, room temperature bore.