Thermal, electrical and magnetic properties of cu-doped CoSi2

Co Si 2 Cu x single– ( = 0 – 0.015) and polycrystals ( = 0 – 0.025) were synthesized to investigate how Cu doping modulates the thermal, electrical, and magnetic properties of CoSi 2 . Temperature–dependent electrical resistivity measurements reveal that 1.5% Cu doping optimally reduces intrinsic resistivity by up to 30% in polycrystals and over 50% in single crystals. Bloch–Grüneisen analysis indicates that electron–phonon scattering dominates at high temperatures, while electron–electron scattering contributes at low temperatures. Magnetoresistance measurements show classical orbital behaviour with near quadratic field dependence at low temperatures, reaching 5.5% at 10 K for optimally doped samples. Kohler scaling analysis reveals a transition from single to multiple scattering regimes with increasing temperature. Specific heat measurements yield Debye temperatures (460–490 K) consistent with resistivity fits, confirming acoustic phonons govern electron–phonon coupling. Total thermal conductivity decreases with Cu doping due to suppressed electronic contribution, while the phononic term increases slightly from lattice softening trends verified by ab initio calculations. All samples exhibit simple Pauli paramagnetism with no Cu–induced ordering. These results demonstrate that Cu acts as a controlled defect center that modulates scattering mechanisms while preserving the metallic ground state, offering a pathway to optimize CoSi 2 for microelectronic applications. • Cu doping reduces CoSi 2 resistivity while preserving metallic behavior and structural integrity. • Temperature-dependent resistivity fits for Cu doped CoSi 2 yield Debye temperatures consistent with specific heat measurements. • Bloch-Grüneisen analysis reveals Cu acts as a controlled defect center, optimizing electron-phonon scattering without altering the phonon spectrum. • Magnetoresistance and Kohler analysis confirm transition from single to multiple scattering regimes with varying Cu concentrations. • DFT calculations validate Cu substitution on Co sites and predict lattice thermal conductivity trends consistent with experimental observations. • All Cu-doped compositions retain simple Pauli paramagnetism with no induced magnetic ordering.