VNU-UET Repository: No conditions. Results ordered -Date Deposited. 2024-03-29T05:13:38ZEPrintshttp://eprints.uet.vnu.edu.vn/images/sitelogo.pnghttps://eprints.uet.vnu.edu.vn/eprints/2021-10-31T00:45:33Z2021-10-31T00:45:33Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/4538This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/45382021-10-31T00:45:33ZKhảo sát sự tương tác của ánh sáng Vis-NIR đến da người
(Interaction of Vis-NIR Light on Human Skin)Hấp thụ của phổ ánh sáng nhìn thấy và cận hồng ngoại (Vis-NIR) phụ thuộc vào cấu trúc tế bào sắc tố (chromophore cells) năm ở lớp biểu bì, lớp hạ bì và lớp mỡ dưới da. Hấp thụ ánh sáng làm thay đổi lượng sắc tố melanin hình thành ở các lớp dưới da, do đó ảnh hưởng đến màu sắc của da người.Cường / Kiên Nguyễn2019-12-24T04:39:03Z2020-12-23T03:14:41Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/3857This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/38572019-12-24T04:39:03ZSTRUCTURAL, MAGNETIC AND ELECTRICAL PROPERTIES
OF Ho AND Ni CO-DOPED BiFeO3 MATERIALSPure BiFeO3 (BFO) and Bi1-xHoxFe0.97Ni0.03O3 (x = 0, 0.025, 0.05, 0.075, and 0.1)
materials were synthesized by a sol-gel method. The influence of (Ho, Ni) co-doping on structural,
magnetic and electrical properties of BFO materials were investigated by different techniques as
X-ray diffraction (XRD), energy dispersion X-ray (EDX), Raman scattering, magnetic hysteresis
(M-H) loops, and complex impedance spectra measurement. XRD results showed that all samples
were crystallized in the rhombohedral structure with R3C space group. Crystal lattice parameters
(a, c) and average crystal size LXRD were (a = 5.584 Å, c = 13.867 Å, LXRD = 60 nm) for pure BFO,
(a = 5.589 Å, c = 13.875 Å, LXRD = 60 nm) for BiFe0.97Ni0.03O3 sample, and then decreased with
increasing of Ho content in (Ho, Ni) co-doped samples. Similarly, Raman scattering spectra
showed the left shift of active modes Fe-O bonds when doping Ni and right shift when co-doping
Ho. These observations confirmed the successful substitution of Ho3+ and Ni2+ ions into the host
BFO crystal lattice. Magnetic hysteresis loops measurement indicated that all samples exhibited
weak ferromagnetic behavior with saturation magnetization Ms and remnant magnetization Mr of
(Ms ~ 0.047 emu/g, Mr ~ 0.008 emu/g) for pure BFO which increased gradually for (Ho, Ni) codoped samples, reached to (Ms ~ 0.702 emu/g, Mr ~ 0.169 emu/g) for x = 0 sample. Origin of the
enhancement of ferromagnetization in (Ho, Ni) co-doped samples have been discussedDinh Tu Buibuidinhtu@vnu.edu.vn