Magnetic and optical properties of (Ga1−xMnx)As diluted magnetic semiconductor quantum wires with above room ferromagnetic transition temperature

2007 ◽  
Vol 101 (2) ◽  
pp. 023508 ◽  
Author(s):  
H. C. Jeon ◽  
T. W. Kang ◽  
T. W. Kim ◽  
Y.-J. Yu ◽  
W. Jhe ◽  
...  
Keyword(s):  
Optical Properties ◽  
Transition Temperature ◽  
Quantum Wires ◽  
Diluted Magnetic Semiconductor ◽  
Magnetic Semiconductor ◽  
Ferromagnetic Transition ◽  
Diluted Magnetic

EFFECTS OF PHOTO-EXCITATION AND MAGNON SCATTERING ON FERROMAGNETIC TRANSITION TEMPERATURE OF THE DILUTED MAGNETIC SEMICONDUCTOR (Ga1 - x, Mnx)As

2011 ◽  
Vol 25 (04) ◽  
pp. 273-280 ◽  
Author(s):  
CHERNET AMENTE ◽  
P. SINGH
Keyword(s):  
Transition Temperature ◽  
Spin Wave ◽  
Wave Scattering ◽  
Diluted Magnetic Semiconductor ◽  
Magnetic Semiconductor ◽  
Ferromagnetic Transition ◽  
Photon Irradiation ◽  
Model Hamiltonian ◽  
Diluted Magnetic ◽  
System Properties

Effects of photo-excitation and spin-wave scattering on magnetization of the diluted magnetic semiconductor (DMS) ( Ga , Mn ) As are theoretically studied. Green function formalism is used to find expression for magnetization and ferromagnetic transition temperature TC starting with a model Hamiltonian consisting of magnons, photons and an interaction of magnons with photons. According to our calculation, there is TC in the absence of magnetic impurity, x = 0, indicating that there could be electronically unpaired influential carriers/holes induced by photon irradiation resulting in residual itinerant band magnetization which can be revealed by experiments. Unusual upturn in magnetization near 0 K temperature values for larger magnon–photon coupling constant is also indicated. Moreover, enhancement of magnetization is established with increase in impurity concentration and even further in the presence of photon–magnon coupling which however decreases due to spin-wave scattering. This leads to the conclusion that at lower temperatures photon irradiation and at higher temperatures spin-wave scattering could affect the system properties predominantly.

scholarly journals Drastic improvement of Curie temperature by chemical pressure in N-type diluted magnetic semiconductor Ba(Zn,Co)$$_{2}$$As$$_{2}$$

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Licheng Fu ◽  
Yilun Gu ◽  
Guoxiang Zhi ◽  
Haojie Zhang ◽  
Rufei Zhang ◽  
...  
Keyword(s):  
Unit Cell Volume ◽  
Diluted Magnetic Semiconductor ◽  
Magnetic Semiconductor ◽  
Vital Role ◽  
Ferromagnetic Transition ◽  
Chemical Pressure ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Diluted Magnetic ◽  
Ferromagnetic Ordering

AbstractWe report the effect of chemical pressure on the ferromagnetic ordering of the recently reported n-type diluted magnetic semiconductor Ba(Zn$$_{1-x}$$ 1 - x Co$$_{x}$$ x )$$_{2}$$ 2 As$$_{2}$$ 2 which has a maximum $$T_C$$ T C $$\sim$$ ∼ 45 K. Doping Sb into As-site and Sr into Ba-site induces negative and positive chemical pressure, respectively. While conserving the tetragonal crystal structure and n-type carriers, the unit cell volume shrink by $$\sim$$ ∼ 0.3$$\%$$ % with 15$$\%$$ % Sr doping, but drastically increase the ferromagnetic transition temperature by 18$$\%$$ % to 53 K. Our experiment unequivocally demonstrate that the parameters of Zn(Co)As$$_{4}$$ 4 tetrahedra play a vital role in the formation of ferromagnetic ordering in the Ba(Zn,Co)$$_{2}$$ 2 As$$_{2}$$ 2 DMS.

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