Depth-dependent defect and residual stress distribution in magnetron sputtered MoN:Cu nanocomposite films by x-ray micro
- PDF / 45,896 Bytes
- 2 Pages / 612 x 792 pts (letter) Page_size
- 65 Downloads / 168 Views
0977-FF08-05
Depth-dependent defect and residual stress distribution in magnetron sputtered MoN:Cu nanocomposite films by x-ray microdiffraction Gang Chen1, Dileep Singh2, Osman Eryilmaz1, Ali Erdemir1, Jules Routbort1, and Wenjun Liu3 1 Energy System Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL, 60439 2 Nuclear Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL, 60439 3 Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL, 60439 We have developed a synchrotron-based x-ray microdiffraction technique for measuring depth-resolved residual stress distribution in nanocrystalline films with submicron resolution [1]. In this study, we further refined this technique and applied it to low-friction and high-hardness Cu-doped MoN films. These magnetron sputtered nanocomposites films consist of MoN, Mo2N, and Cu phases, whose ratio depends on Cu concentration. By using the microdiffraction technique, we discovered that both the deviatoric and the hydrostatic components of the residual stresses depend on the film depth (Fig.1). The former indicates depth-dependent distribution of biaxial stresses, while the latter implies depth-dependent defect distribution, which also depends on Cu concentration. Thermal annealing of the nanocomposite film partially relives the stress, significantly reduces the lattice spacing, and eliminates the defect gradients. These results suggest that interstitial N may play an important role in the lattice expansion and the defect gradients formed during the non-equilibrium sputtering process. Our study provides fresh insights into understanding the structure-property relations in the magnetron sputtered MoN:Cu nanocomposites films.
Biaxial Stress (GPa)
1.450
-1.6 1.448
-1.8 -2.0
1.446
-2.2 1.444
-2.4 -2.6
1.442
-2.8 0.0
0.5
1.0
1.5
2.0
2.5
3.0
Hydrostatic Lattice Spacing (Å)
-1.4
Depth from film surface (µm) Figure1: Distributions of biaxial residual stress and hydrostatic lattice spacing in a MoN:Cu film as a function of film depth.
Mater. Res. Soc. Symp. Proc. Vol. 977 © 2007 Materials Research Society
Acknowledgements This work is supported by the Department of Energy (DOE) FreedomCAR and Vehicle Technologies Program. Use of the Advanced Photon Source is supported by the DOE Office of Science under Contract No. DE-AC02-06CH11357.
1
G. Chen, D. Singh, O. Eryilmaz, J. Routbort, B. C. Larson, and W. Liu, Appl. Phys. Lett. 89, 172104 (2006).
Data Loading...
