This paper reports that （Ga, Mn）N is prepared using implantation of 3at.% Mn Ions into undoped GaN. Structural characterization of the crystals was performed using x-ray diffraetion（XRD）. Detailed XRD measurements...This paper reports that （Ga, Mn）N is prepared using implantation of 3at.% Mn Ions into undoped GaN. Structural characterization of the crystals was performed using x-ray diffraetion（XRD）. Detailed XRD measurements have revealed the characteristic of Mn-ion implanted GaN with a small contribution of other compounds. With Raman spectroscopy measurements, the spectra corresponding to the intrinsic GaN layers demonstrate three Raman active excitations at 747, 733 and 566 cm-1 identified as EI（LO）, A1 （LO） and E~, respectively. The Mn-doped GaN layers exhibit additional excitations at 182, 288, 650 725, 363, 506cm^-1 and the vicinity of E~ mode. The modes observed at 182, 288, 650 725em 1 are assigned to macroscopic disorder or vacancy-related defects caused by Mn-ion implantation. Other new phonon modes are assigned to Mnx-Ny, Gax-Mny modes and the local vibrational mode of Mn atoms in the （Ga, Mn）N, which are in fair agreement with the standard theoretical results.展开更多
In this paper, we report the use of blowing nitrogen gas for the successful fabrication of a composite layer composed of Ti/TiN on a substrate of commercially pure titanium （cp-2） using the friction stir processing ...In this paper, we report the use of blowing nitrogen gas for the successful fabrication of a composite layer composed of Ti/TiN on a substrate of commercially pure titanium （cp-2） using the friction stir processing technique. The prepared composite layer was characterized by X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectrometry. The maximum microhardness of the Ti/TiN composite reached 1024 HV, which is 6.4 times higher than that of the titanium substrate. The results of wear test indicated that the Ti/TiN composite layer possesses excellent abrasive and adhesive wear resistance because of the formation of the TiN and its high hardness.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 90407014)
文摘This paper reports that （Ga, Mn）N is prepared using implantation of 3at.% Mn Ions into undoped GaN. Structural characterization of the crystals was performed using x-ray diffraetion（XRD）. Detailed XRD measurements have revealed the characteristic of Mn-ion implanted GaN with a small contribution of other compounds. With Raman spectroscopy measurements, the spectra corresponding to the intrinsic GaN layers demonstrate three Raman active excitations at 747, 733 and 566 cm-1 identified as EI（LO）, A1 （LO） and E~, respectively. The Mn-doped GaN layers exhibit additional excitations at 182, 288, 650 725, 363, 506cm^-1 and the vicinity of E~ mode. The modes observed at 182, 288, 650 725em 1 are assigned to macroscopic disorder or vacancy-related defects caused by Mn-ion implantation. Other new phonon modes are assigned to Mnx-Ny, Gax-Mny modes and the local vibrational mode of Mn atoms in the （Ga, Mn）N, which are in fair agreement with the standard theoretical results.
文摘In this paper, we report the use of blowing nitrogen gas for the successful fabrication of a composite layer composed of Ti/TiN on a substrate of commercially pure titanium （cp-2） using the friction stir processing technique. The prepared composite layer was characterized by X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectrometry. The maximum microhardness of the Ti/TiN composite reached 1024 HV, which is 6.4 times higher than that of the titanium substrate. The results of wear test indicated that the Ti/TiN composite layer possesses excellent abrasive and adhesive wear resistance because of the formation of the TiN and its high hardness.
