Nuclear energy has been increasingly recognized as an effective and low carbon-emission energy source. Nuclear reactors are susceptible to adverse effects, which can lead to potentially severe consequences, though they are low in probability. To ensure safety and improved monitoring of reactors, there have been increasing interests in developing sensors to monitor key parameters relating to the status within a reactor. In order to improve sensor accuracy, high-resolution characterization of cladding materials can be utilized to correlate with sensor output. A common issue with zirconium cladding is the so-called "breakaway phenomenon", a critical factor seen as the transition from an initially passive zirconia to an active material. Existing research presents many factors that contribute to the breakaway mechanism, ultimately resulting in difficulty to predict its activation and propagation. As part of the effort to develop sensors, an improved understanding of pre- and post-breakaway zirconium alloys (Zr, Zr-2.65Nb, Zry-3, and Zry-4) is accomplished with Raman spectroscopy, scanning Kelvin probe force microscopy, and atom probe tomography.