A New SQUID Magnetometer for Extreme Conditions Research

磁性材料广泛应用于日常生活中，从冰箱磁铁到记录媒体。测量材料对外部磁场的响应（磁化强度）对于磁性和相关材料的研究至关重要。磁化强度由磁力计测量，其中最敏感的是基于超导量子干涉器件（SQUID）。爱丁堡大学包含各种材料的研究小组，如多铁性和磁阻氧化物，分子磁性固体，有机和单分子磁体，受抑磁性，超导体和量子临界现象，以及磁性地质材料。这项研究有助于发现一系列新材料，并更好地了解基本的物理和矿物学过程。需要一种新的SQUID磁强计来促进我们的研究，既可以取代15年前不再可靠的旧机器，也可以扩展在更高温度（高达800 K）和磁场（高达7 T）下进行研究的可能性。SQUID磁强计将位于我们的极端条件科学中心（CSEC），当地的专业知识将用于设计和建造新的压力插入件。一种新型的双壁活塞气缸单元将能够将这种类型的插入件的最大压力扩展到3GPa（约30，000 atm）。我们还将设计和建造一个开创性的对砧单元使用莫桑石（碳化硅）砧，这是一个很好的和廉价的替代钻石。这将使最先进的高压SQUID磁力测量能够在高达5 GPa的压力下进行。

Magnetic materials are widely used in everyday life, from fridge magnets to recording media. Measuring the response of a material (the magnetisation) to an external magnetic field is essential for studies of magnetic and related materials. Magnetisation is measured by magnetometers and the most sensitive of these are based on Superconducting Quantum Interference Devices (SQUIDs). The University of Edinburgh contains groups working on a variety of materials such as multiferroic and magnetoresistive oxides, molecular magnetic solids, organic and single molecule magnets, frustrated magnetism, superconductors and quantum critical phenomena, and magnetic geomaterials. This research contributes to the discoveries of a range of new materials and greater understanding of fundamental physical and mineralogical processes. A new SQUID magnetometer is needed to facilitate our research, both to replace a 15-year old machine that is no longer reliable, and to extend possibilities for research at higher temperatures (up to 800 K) and magnetic fields (up to 7 T).Applying pressure to tune and change magnetic properties is an additional key feature of this proposal. The SQUID magnetometer will be located in our Centre for Science at Extreme Conditions (CSEC), where local expertise will be used to design and construct new pressure inserts. A novel, double-walled piston cylinder cell will enable extend the maximum pressure for this type of insert up to 3 GPa(approximately 30,000 atm.). We will also design and build a pioneering opposed-anvil cell using moissanite (silicon carbide) anvils, which are a good and inexpensive alternative to diamonds. This will enable state-of-the-art high pressure SQUID magnetometry to be performed at pressures of up to 5 GPa.