In the context of nanotechnology, ATR is particularly valuable because it can analyze very thin films and surface layers, which are often too delicate or small for conventional methods. The key to ATR's success is the total internal reflection phenomenon. When an infrared beam strikes a sample at a specific angle, an evanescent wave penetrates a short distance into the material. This penetration depth is typically in the range of nanometers to micrometers, making it ideal for nanoscale analysis.
