MAGNETIC PROPERTIES OF La-DOPED AND Cu-DOPED ZnO NANOWIRES FABRICATED BY HYDROTHERMAL METHOD

2013 ◽  
Vol 27 (15) ◽  
pp. 1362006 ◽  
Author(s):  
SAN-LIN YOUNG ◽  
HONE-ZERN CHEN ◽  
MING-CHENG KAO ◽  
CHUNG-YUAN KUNG ◽  
CHEN-CHENG LIN ◽  
...  
Keyword(s):  
Growth Rate ◽  
Magnetic Properties ◽  
Room Temperature Ferromagnetism ◽  
Substitution Effect ◽  
Hexagonal Structure ◽  
Zno Nanowires ◽  
Cu Doping ◽  
La Doping ◽  
Doped Zno ◽  
La Doped

La -doped and Cu -doped ZnO nanowires have been prepared to compare the substitution effect on the microstructural and magnetic properties. The XRD patterns of both compositions with single diffraction peak (002) show the same wurtzite hexagonal structure. The growth rate of the ZnO nanowires were enhanced by Cu doping, which were different from the suppression of growth rate by La doping. Room temperature ferromagnetism is observed for all ZnO , Cu -doped ZnO and La -doped ZnO nanowires. The saturation magnetizations are 0.102, 0.232 and 0.04 emu/g for ZnO , Cu -doped ZnO and La -doped ZnO nanowires, respectively. The results showed that the ferromagnetism is restrained by Cu doping, but enhanced by the La doping.

Co-DOPED ZnO NANOWIRES GROWN BY VAPOR–LIQUID–SOLID METHOD: STRUCTURAL, OPTICAL AND MAGNETIC STUDIES

NANO ◽  
2012 ◽  
Vol 07 (04) ◽  
pp. 1250028 ◽  
Author(s):  
BAPPADITYA PAL ◽  
SOUMEN DHARA ◽  
P. K. GIRI
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Visible Region ◽  
Magnetic Behavior ◽  
Hexagonal Structure ◽  
Zno Nanowires ◽  
Magnetic Studies ◽  
Microscopy Imaging ◽  
Doped Zno ◽  
Co Doped

We report on the growth of Co -doped ZnO nanowires (NWs) on Si substrate using a self-catalytic vapor deposition method from a Co -doped ZnO nanopowder source and study its structural, optical and magnetic properties for the as-grown and rapid thermal annealed samples. Co (5%)-doped ZnO ( ZnCoO ) nanoparticles (NPs) are used as source material for the growth process. Electron microscopy imaging clearly reveals the formation of long ZnO NWs with uniform diameter. X-ray diffraction analysis confirms the single crystalline hexagonal structure of Co -doped ZnO NWs without impurities of metallic cobalt or other phases. Micro-Raman studies of doped samples show doping/disorder induced additional modes as compared to the undoped ZnO . Room temperature photoluminescence spectra of the doped ZnO NWs show strong emission band at ~380 nm and no significant emission was observed in the visible region indicating low defect content in the NWs. The field dependent magnetization (M–H curve) measured at room temperature exhibits paramagnetic nature for the NWs with the magnetic moment in the range 2–3.7 milli-emu/cm2 for the applied field of 2 Tesla, while the source ZnCoO NPs exhibit room temperature ferromagnetism with saturation magnetization ~6 emu/g. Possible mechanism of alteration in magnetic behavior in doped NWs are discussed based on the growth conditions and role of defects.

DEFECT FORMATION AND MAGNETIC PROPERTIES OF COPPER DOPED ZnO NANOWIRES

2012 ◽  
Vol 26 (13) ◽  
pp. 1250081 ◽  
Author(s):  
LI-BIN SHI
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Defect Formation ◽  
Zno Nanowires ◽  
Energy Calculation ◽  
Generalized Gradient ◽  
Total Energies ◽  
Doped Zno ◽  
P Type

Theoretical calculation based on density functional theory (DFT) and generalized gradient approximation (GGA) has been carried out in studying defect formation energies, ionization energies and magnetic properties of copper doped ZnO nanowires (NW). It is found from formation energy calculation that n-type Cu-doped ZnO NW is non-FM and p-type Cu-doped ZnO NW could be FM. The results show that total energies of FM coupling are lower than those of AFM coupling for majority of 12 configurations, indicating that the FM coupling between Cu atoms is more stable than AFM coupling. The FM stability is interpreted by Cu 3d energy level coupling. In addition, zinc and oxygen vacancies affecting FM coupling is also discussed. It is found that FM coupling can be tuned by zinc and oxygen vacancies.

Synthesis, micro-structural and magnetic properties of Mn-doped ZnO nanowires

CrystEngComm ◽  
2011 ◽  
Vol 13 (7) ◽  
pp. 2566 ◽  
Author(s):  
Yangyan Rao ◽  
Haiyang Xu ◽  
Yao Liang ◽  
Suikong Hark
Keyword(s):  
Magnetic Properties ◽  
Zno Nanowires ◽  
Structural And Magnetic Properties ◽  
Doped Zno ◽  
Mn Doped

Trapping of Ce electrons in band gap and room temperature ferromagnetism of Ce4+ doped ZnO nanowires

2009 ◽  
Vol 106 (8) ◽  
pp. 083515 ◽  
Author(s):  
Javed Iqbal ◽  
Xiaofang Liu ◽  
Huichao Zhu ◽  
Chongchao Pan ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Zno Nanowires ◽  
Doped Zno

DEFECT FORMATION AND MAGNETIC PROPERTIES OF Co-DOPED ZnO NANOWIRES

NANO ◽  
2013 ◽  
Vol 08 (02) ◽  
pp. 1350021 ◽  
Author(s):  
LI BIN SHI ◽  
GUO QUAN QI ◽  
YING FEI
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Defect Formation ◽  
Density Functional Method ◽  
Zno Nanowires ◽  
Generalized Gradient ◽  
Surface Sites ◽  
Doped Zno ◽  
Formation Energies ◽  
Co Doped

The defect formation energies and magnetic properties in Co -doped ZnO nanowires (NWs) are studied using the first-principle density functional method within the generalized gradient approximation (GGA) and GGA + U schemes. It is found that Co impurity has lower formation energies in the surface sites, indicating that Co impurity occupies preferably surface sites of NWs. Ferromagnetic (FM) and antiferromagnetic (AFM) coupling are investigated by GGA and GGA + U methods. The results show that the AFM coupling in energy is lower than the FM coupling, which indicates that AFM coupling is more stable. The magnetic properties can be mediated by the vacancies [ VO(B) and VZn(B) ] and interstitials [ IZn(oct) ]. The stability of the FM and AFM can be explained by the Co 3d energy level coupling.

Ferromagnetic and Optical Properties of Partially Cu-Doped ZnO Films

2009 ◽  
Vol 64 (11) ◽  
pp. 765-768 ◽  
Author(s):  
Fan-Yong Ran ◽  
Masaki Tanemura ◽  
Yasuhiko Hayashi ◽  
Norihiro Ide ◽  
Masao Imaoka ◽  
...  
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Room Temperature Ferromagnetism ◽  
Intrinsic Property ◽  
Zno Films ◽  
Cu Doping ◽  
Partial Area ◽  
Doped Zno

Wurtzite structure ZnO films (3×3 mm2) with a partial-area Cu doping were successfully prepared using a micro-area Ar+-ion beam (~ 380 μm in diameter) and a simultaneous Cu supply at room temperature. A Cu2O phase was formed in the ZnO films by Cu doping. The partially Cu-doped ZnO films exhibited room-temperature ferromagnetism (RTFM) with a saturation magnetization of 1.6×10−5 emu and a coercive field of 40 Oe. Since Zn, Cu, and their compounds are not ferromagnetic, the observed RTFMis attributed to the intrinsic property of Cu-doped ZnO films. As confirmed by the low temperature photoluminescence (PL) spectra, no serious optical damage was recognized in the region without Ar+-ion irradiation. Thus, it was believed that the micro-area Ar+-ion irradiation with a simultaneous Cu supply was promising to integrate the magnetic and optical properties of ZnO-based materials.

Sign in / Sign up

Export Citation Format

Share Document