KEYWORDS: Magnetism, Crystals, Semiconductors, Manganese, Magnetic semiconductors, Ions, Crystallography, Temperature metrology, Chemical elements, Statistical analysis
The peculiarities of the exchange interaction between the carrier spin and localized spin moments of magnetic ions in narrow-gap quaternary solid solutions Hg1-x-yCdxMnyTe and Hg 1-x-yCdxMnySe are studied by means of photoluminescence in magnetic field and magneto transport (Shubnikov-de Haas oscillations). It is shown that the s-p hybridization of electron wavefunctions leads to the violation of the conventional selection rules, and the spin-flip processes contribute both in the optical and in the electrical phenomena. The exchange constant α turns out in a complicated fuction α of energy gap Eg and electron concentration which changes from positive α No = 0.15 eV to negative α No = -0.28 eV values which are typically accepted for wide gap semimagnetic semiconductors.
Epitaxial MnxHg1-xTe layers grown by the liquid phase method at temperatures 848K and 793K are investigated. Due to diffusion of Cd from substrate Cd0.96Zn0.04Te obtained layers are four-component. Results of conductivity and Hall measurements show that the graded-gap layer gives noticeable contribution to the transport characteristics.
The comparison of actual manganese concentration in (Hg,Mn)Te samples grown by liquid phase epitaxy on CdTe and Cd0.96Zn0.04Te substrates to values obtained from the phase diagram of Hg-Mn-Te system reveals considerable discrepancies. The thermodynamic analysis made in assumption that the manganese concentration in the melting is low strained solid phase and superolled liquid one, i.e. the crystallization process is affected by elastic strain in epitaxial layer caused by lattice mismatch between substrate and film. It is shown also that the model of complete association in liquid phase do not provide a good agreement with experimental data.
Optical and photoelectrical properties of both as-grown and annealed at 600 C during five hours CdTe:V crystals with Vanadium concentration in liquid phase of 5 X 1018cm-3 and 5 X19cm-3 were investigated. Presented data are based on investigation of photoluminescence (PL) spectra and spectral dependence of photoconductivity (PC). The effect of PL band kindling has been detected with maximum at 1.55 eV in crystals of Nv equals 5 X 1018 cm-3 doping concentration. The effect is accompanied by dramatic increase of crystals' resistance. As mechanism responsible for formation of high- resistance state the self-compensation of the impurities with creation of complexes that include isolated Vanadium and vacancy in the metal sublattice is considered.
Electrical and optical properties of CdTe doped by Vanadium in the concentration range from 5.1018cm-3 to 5.1019cm-3 are studied with the use of a set of experimental methods: EPR, photoluminescence, photoconductivity, and thermostimulated conductivity. It is shown that doping CdTe by Vanadium leads to formation of defect that manifests itself as deep donor center with optical and thermal activation energies equal to 1.30 eV and 0.71 eV respectively.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.