The ionization process of B2＋ by H＋ impact is studied using the continuum-distorted-wave eikonal-initial-state （CDW-EIS） method and the modified free electron peak approximation （M-FEPA）, respectively. Total, si...The ionization process of B2＋ by H＋ impact is studied using the continuum-distorted-wave eikonal-initial-state （CDW-EIS） method and the modified free electron peak approximation （M-FEPA）, respectively. Total, single-, and double- differential cross sections from ls and 2s orbitals are presented for the energy range from 10 keV/u to 10 MeV/u. Com- parison between the results from the two methods demonstrates that the total and single-differential cross sections for the high-energy incident projectile case can be well evaluated using the simple M-FEPA model. Moreover, the M-FEPA model reproduces the essential features of the binary-encounter （BE） bump in the double-differential cross sections. Thus, the BE ionization mechanism is discussed in detail by adopting the M-FEPA model. In particular, the double- and single- differential cross sections from the 2s orbital show a high-energy hip, which is different from those from the ls orbital. Based on Ref. [1], the Compton profiles of B2＋ for ls and 2s orbitals are given, and the hips in DDCS and SDCS from the 2s orbital are explained.展开更多
Based on first-principles calculations, the electronic and magnetic properties of undoped and Li-doped rutile TiO2 have been studied. The results demonstrate that a cation vacancy can arouse ferromagnetism in TiO2 and...Based on first-principles calculations, the electronic and magnetic properties of undoped and Li-doped rutile TiO2 have been studied. The results demonstrate that a cation vacancy can arouse ferromagnetism in TiO2 and the magnetic moment mainly comes from p orbitals of O atoms around the Ti vacancy. However, the Ti vacancy under normal conditions is very difficult to form due to its high formation energy. Our calculations indicate that Li-doped TiO2 can reduce the formation energy while keeping the magnetism. The large magnetization energy indicates that Li-doped TiO2 is a promising room-temperature diluted magnetic semiconductor.展开更多
基金Project supported by the National Basic Research Program of China (Grant No. 2013CB922200)the National Natural Science Foundation of China (Grant Nos. 11005049, 11025417, 10979007, and 10974021)
文摘The ionization process of B2＋ by H＋ impact is studied using the continuum-distorted-wave eikonal-initial-state （CDW-EIS） method and the modified free electron peak approximation （M-FEPA）, respectively. Total, single-, and double- differential cross sections from ls and 2s orbitals are presented for the energy range from 10 keV/u to 10 MeV/u. Com- parison between the results from the two methods demonstrates that the total and single-differential cross sections for the high-energy incident projectile case can be well evaluated using the simple M-FEPA model. Moreover, the M-FEPA model reproduces the essential features of the binary-encounter （BE） bump in the double-differential cross sections. Thus, the BE ionization mechanism is discussed in detail by adopting the M-FEPA model. In particular, the double- and single- differential cross sections from the 2s orbital show a high-energy hip, which is different from those from the ls orbital. Based on Ref. [1], the Compton profiles of B2＋ for ls and 2s orbitals are given, and the hips in DDCS and SDCS from the 2s orbital are explained.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11005049 and 61006051)
文摘Based on first-principles calculations, the electronic and magnetic properties of undoped and Li-doped rutile TiO2 have been studied. The results demonstrate that a cation vacancy can arouse ferromagnetism in TiO2 and the magnetic moment mainly comes from p orbitals of O atoms around the Ti vacancy. However, the Ti vacancy under normal conditions is very difficult to form due to its high formation energy. Our calculations indicate that Li-doped TiO2 can reduce the formation energy while keeping the magnetism. The large magnetization energy indicates that Li-doped TiO2 is a promising room-temperature diluted magnetic semiconductor.
