integrated differential phase contrast

**iDPC** (Integrated Differential Phase Contrast) is a **STEM technique that integrates the DPC signal to recover the projected electrostatic potential** — providing images proportional to the specimen potential rather than its gradient, enabling direct imaging of light and heavy atoms simultaneously. **How Does iDPC Work?** - **DPC**: Measure the beam deflection (proportional to the gradient of the projected potential). - **Integration**: Numerically integrate the 2D DPC vector field to recover the scalar potential. - **Result**: Images where contrast is proportional to the projected electrostatic potential (all atoms visible). - **4D-STEM**: Modern implementations use pixelated detectors for more accurate DPC and iDPC. **Why It Matters** - **Universal Contrast**: Both light (O, N) and heavy (metal) atoms visible in the same image — unlike HAADF or ABF alone. - **Linear Contrast**: Image intensity is linearly proportional to projected potential — quantitative interpretation. - **Beam-Sensitive**: Works at low electron doses, important for beam-sensitive materials (zeolites, MOFs). **iDPC** is **the electrostatic potential map** — integrating beam deflection to produce images where every atom, light or heavy, is visible.