A New SQUID Magnetometer for Extreme Conditions Research

磁性材料广泛应用于日常生活中，从冰箱磁铁到记录介质。测量材料(磁化作用)对外部磁场的响应对于研究磁性材料和相关材料是必不可少的。磁化作用是由磁力计测量的，其中最敏感的是基于超导量子干涉器件(SQUID)。爱丁堡大学的研究小组从事各种材料的研究，如多铁性和磁阻氧化物、分子磁性固体、有机和单分子磁体、受挫磁性、超导体和量子临界现象，以及磁性岩土材料。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。为了方便我们的研究，需要一种新的SQUID磁强计，以取代不再可靠的15年旧机器，并扩大在更高的温度(高达800K)和磁场(高达7T)下进行研究的可能性。施加压力来调整和改变磁性是这项提议的另一个关键特征。SQUID磁力仪将放置在我们的极端条件科学中心(CSEC)，在那里将使用当地的专业知识来设计和建造新的压力插件。一种新颖的双壁活塞气缸单元将使这种类型的插件的最大压力提高到3 Gpa(约30,000大气压)。我们还将使用碳化硅(碳化硅)顶锤设计和制造一种开创性的对接顶锤单元，这是一种良好且廉价的钻石替代品。这将使最先进的高压SQUID磁测量能够在高达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.