Undergraduate Honors Theses

Thesis Defended

Spring 2019

Document Type


Type of Thesis

Departmental Honors



First Advisor

Minhyea Lee


Magnetic phase transitions between non-trivial ordered states are investigated through AC Susceptibility measurements. An AC Susceptometer was built for the purpose of detecting variations in a material’s magnetic structure in response to adjustments of external conditions. The AC Susceptometer is sensitive to subtle changes in magnetic ordering, indicated by distinct features in measured AC Susceptibility data when a phase transition occurs. The coil design and characterization is discussed in detail. The dependence of AC Susceptibility on temperature and applied DC field conditions are explored in samples of Cr1/3NbS2, 10% Iron-doped MnSi (Mn0.9Fe0.1Si), and CeRu2Ga2B (CRGB). Distinct and well-defined phase boundaries are reported, highlighting the advantages of this AC Susceptometry technique.