Temperature and baric dependence of nuclear quadruple resonance spectra in indium and gallium monoselenides

A Low-Cost Digital Pulsed Coherent Spectrometer for Investigation of NQR in Layered Semiconductor GaSe and InSe Crystals

“…Due to the presence of polytypes of εand γ-modifications in the crystal, the spectrum consists of two groups of lines offset by 52.14 kHz on the frequency scale. 20.5 MHz, 30.75 MHz and 41 MHz are typical for InSe [23]. The complexity of NQR spectra can also be noticed in the waveform of the FID (Figure 13).…”

“…The observed spectrum is inherent in the mixture of polytypes of ε-and γ-modifications in the InSe crystalline matrix. 20.5 MHz, 30.75 MHz and 41 MHz are typical for InSe [23]. The complexity of NQR spectra can also be noticed in the waveform of the FID (Figure 13).…”

“…With a view to improve structural perfection and for ordering of polytypes, a long-term annealing with a gradual reduction of annealing temperature was used. The degree of monocrystallicity and structural perfection of samples were determined by X-ray topography methods, as well as NQR methods [23]. Samples cut from these ingots were investigated.…”

“…As the results of the research have shown, the characteristics of the proposed spectrometer make it effective when used to observe FID signals of a significant number of isotopes of chemical elements with quadrupolar nuclei ( 14 N, 35 Cl, 63 Cu, 69 Ga, 71 Ga, 113 In, 115 In and others) in the frequency range 1-50 MHz. The complex multiple NQR spectra are located in 4 bands with central frequencies 10.25 MHz, 20.5 MHz, 30.75 MHz and 41 MHz are typical for InSe [23]. The complexity of NQR spectra can also be noticed in the waveform of the FID (Figure 13).…”

Simulation of Magnetic Field Topology in a Saddle-Shaped Coil of Nuclear Quadrupole Resonance Spectrometer

“…The quality of starting materials is determined by the presence of dislocations and structural defects in the layered semiconductor single crystals. One of modern and sensitive methods of studying the quality of layered semiconductors is nuclear quadrupole resonance (NQR) method [2]. Using this method permits consecutive scanning of the entire volume of layered semiconductor sample, which makes it possible to judge on crystal perfection by the obtained NQR spectra.…”