Nanoindentation and Brillouin light scattering studies of elastic moduli of sodium silicate glasses

► Na2O-SiO2 glasses were studied by nanoindentation and Brillouin light scattering. ► Good match of Young's modulus between these two methods in glasses of < 20% Na2O. ► Large difference in values between these two methods in glasses with higher Na2O. ► Pile-up around indents in glasses with higher Na2O explains the large discrepancy.