Cryogen-free physical property measurement system (PPMS)

作为几个正在进行的研究项目的一部分，热电薄膜和纳米颗粒系统的输运实验研究正在进行。这需要一个无低温的测量系统来表征物理固态特性。研究的重点是依赖于温度和磁场的电、热输运性质以及比热。所需的温度范围为1.8 K至400 K，所需的磁场范围可达9 t。工作组目前没有可用于低温表征塞贝克系数，导热系数和比热的设备。现有设备可以表征磁阻和霍尔电阻，但仅限于高达4 t的磁场范围。使用该设备，该磁场范围将果断扩展到高达9 t的磁场范围。由于教师无法选择返回气态氦，因此采购无低温（“闭合循环”）设备势在必行。

As part of several ongoing research projects, experimental research on transport in thermoelectric thin films and nanoparticles system is being performed. This requires a cryogen-free measurement system for the characterization of physical solid-state properties. The focus of the investigations is the temperature and magnetic field dependent electrical and thermal transport properties as well as the specific heat. The desired temperature range is from 1.8 K to 400 K, the desired magnetic field range up to 9 T. The working group currently has no device available for the low-temperature characterization of the Sebeeck coefficient, thermal conductivity and specific heat. The characterization of magnetoresistance and Hall resistance are possible with existing devices, but are limited to a field range of up to 4 T. With this device, this field range will be decisively expanded to a magnetic field range of up to 9 T. Due to the fact that the faculty does not have the option of returning gaseous helium, the procurement of a cryogen-free ("closed-cycle") device is imperative.