Nitrogen implantation into amorphous carbon has been studied at various implantation temperatures by using 100 keVN+at 5&mgr;A and fluences of2×1017ions/cm2. The apparent surface hardness and elastic modulus from nanoindentation are well correlated with an asymmetric diffuse peak at around 1500cm−1and a broad band at∼700cm−1in the Raman spectra. Both the enhanced strengths and Raman characteristics show very weak Arrhenius-type implantation-temperature dependence with activation enthalpies of approximately 20 meV in the temperature range 223−1073 K. ©1997 American Institute of Physics.