Used as a high-k dielectric material in semiconductor devices, especially in advanced transistor gate stacks for integrated circuits. Enables reduction of gate leakage current while maintaining high capacitance, critical for scaling down transistors in modern microprocessors. Also applied in resistive switching memory devices and as a component in optical coatings due to its high refractive index and durability. Serves as a potential material in nuclear reactors as a neutron absorber because of hafnium’s high neutron capture cross-section.