Advancing precision in Hall effect through localized heating with a compact design

Abstract

We have developed a versatile, fully automated Hall measurement setup for operations between room temperature and 750 K and in magnetic fields up to ±10 kOe. Our compact sample holder design with localized heating and minimal heat losses enables precise temperature stability (better than ±10 mK at 750 K) and low power consumption (20–25 W). The setup is housed within a 26 mm air gap between the pole pieces of an electromagnet. The sample holder, enclosed in a quartz tube for a controlled atmosphere, can accommodate various sample shapes and sizes, which can be contacted using adjustable pressure-point contacts. Despite its compact size, bulk thermoelectric samples measuring up to 10 mm laterally can be analyzed successfully. A phase-sensitive lock-in technique and electromagnetic shielding ensure excellent sensitivity, allowing nanovolt Hall signal measurements in high-carrier-concentration samples. We have successfully applied this setup to diverse materials, including a lightly doped germanium (1014 cm−3), degenerate semiconductors from the half-Heusler family (1021 cm−3), and superionic thermoelectrics (1018 cm−3), demonstrating its versatility and reliability. Our results align well with those from commercial systems where available.