Inelastic X-Ray Scattering Studies of Phonon Dispersion in PbTe and (Pb,Cd)Te Solid Solution

Abstract

PbTe and its solid solution (Pb,Cd)Te containing 2% of CdTe and PbTe grown by self-selecting vapour growth technique were investigated by inelastic X-ray scattering using synchrotron radiation. The ID28 beamline at ESRF with the incident photon energy of 17794 eV and the energy resolution of 3 meV was applied for that purpose. The measurements were performed at room temperature along [001]-type high symmetry direction in the Brillouin zone. In spite of a very low energy of phonon branches they can be determined by inelastic X-ray scattering with a high accuracy. The transversal acoustic phonon dispersion obtained by inelastic X-ray scattering corresponds well to those resulting from inelastic neutron scattering measurements and ab initio calculations. Apart from expected structures corresponding to the bulk phonons an additional scattering related to the crystal surface properties was observed in the inelastic X-ray scattering spectra. The analysis performed with the use of secondary ion mass spectroscopy technique demonstrated a presence of a thin oxide layer at sample surfaces.

Microhardness and the Young Modulus of Thin, MBE-Grown, (Sn,Mn)Te Layers Containing up to 8% of Mn

“…The MnTe crystallizes in the hexagonal structure of the NiAs type ( [13] and references therein), the metastable, zinc blende phase of this compound only can also be obtained by MBE (see, e.g., [14]). The observed qualitative composition dependence of the microhardness in (Sn,Mn)Te thin layers is similar to that observed in (Pb,Sn)Te bulk crystal [15] but differs significantly from that recently observed for several PbTe-based solid solutions containing Cd [16,17], Ge [18], or Ca [19]. For example using the same experimental setup the determined Young modulus was also a constant value in (Pb,Cd)Te solid solution but the microhardness increased by almost 50% in a similar composition range [17].…”

“…The observed qualitative composition dependence of the microhardness in (Sn,Mn)Te thin layers is similar to that observed in (Pb,Sn)Te bulk crystal [15] but differs significantly from that recently observed for several PbTe-based solid solutions containing Cd [16,17], Ge [18], or Ca [19]. For example using the same experimental setup the determined Young modulus was also a constant value in (Pb,Cd)Te solid solution but the microhardness increased by almost 50% in a similar composition range [17]. The microhardness of (Pb,Zn)Se and (Pb,Cd)Se solid solutions containing up to a few percent of Zn and Cd, respectively, also significantly increases with an increasing dopant metal content [20].…”

Hardening of (Pb,Cd)Te Crystal Lattice with an Increasing CdTe Content in the Solid Solution

“…2 in Ref. [13]. The high accuracy of this approach for both structural as well as dynamical properties of solids was confirmed in many papers (see, e.g.…”

The Young Modulus and Microhardness Anisotropy in (Pb,Cd)Te Solid Solution Crystallizing in the Rock Salt Structure and Containing 5% of Cd

“…Since 2009 several physical properties of these crystals have been both investigated and reported (see, e.g., [11][12][13][14]). Quite recently, we have examined selected mechanical properties of this particular semiconductor.…”