TY - JOUR

T1 - Quadrupole Spin–Lattice Relaxation of 69Ga and 71Ga in a GaAs Semi-insulator Crystal

AU - Рочев, Андрей Михайлович

AU - Микушев, Владимир Михайлович

AU - Чарная, Елена Владимировна

N1 - Conference code: 22

PY - 2025/8

Y1 - 2025/8

N2 - NMR studies of spin–lattice relaxation were carried out for two gallium isotopes, 69Ga and 71Ga, for an undoped semi-insulator GaAs crystal under the additional continuous magnetic saturation of the nuclear spin systems at the Larmor frequencies. The magnetization recovery after inversion was observed within the temperature range from 80 to 300 K using a Bruker Avance 400 pulse spectrometer. Two main contributions to relaxation due to the hyperfine coupling with the electron centers accompanied by spin diffusion and due to the spin–phonon interaction in the regular crystal lattice were separated by suppressing the first one. Both contributions to relaxation were found to be of the quadrupole nature and followed the temperature dependence predicted for quadrupole relaxation owing to the modulation by thermal phonons of the electric field gradients at nuclei. The results obtained are consistent with the suggestion that the quadrupole hyperfine coupling dominates for nuclei in the neighborhood of the electron centers and the rapid spin diffusion approximation is satisfied.

AB - NMR studies of spin–lattice relaxation were carried out for two gallium isotopes, 69Ga and 71Ga, for an undoped semi-insulator GaAs crystal under the additional continuous magnetic saturation of the nuclear spin systems at the Larmor frequencies. The magnetization recovery after inversion was observed within the temperature range from 80 to 300 K using a Bruker Avance 400 pulse spectrometer. Two main contributions to relaxation due to the hyperfine coupling with the electron centers accompanied by spin diffusion and due to the spin–phonon interaction in the regular crystal lattice were separated by suppressing the first one. Both contributions to relaxation were found to be of the quadrupole nature and followed the temperature dependence predicted for quadrupole relaxation owing to the modulation by thermal phonons of the electric field gradients at nuclei. The results obtained are consistent with the suggestion that the quadrupole hyperfine coupling dominates for nuclei in the neighborhood of the electron centers and the rapid spin diffusion approximation is satisfied.

KW - contributions to nuclear spin-lattice relaxation

KW - NMR

KW - continuous magnetic saturation

KW - suppression of relaxation due to electron centers

KW - semi-insulator GaAs crystal

UR - https://www.mendeley.com/catalogue/294faaa1-a1fc-30d3-857f-30f1860a3966/

U2 - 10.1007/s00723-025-01764-1

DO - 10.1007/s00723-025-01764-1

M3 - Conference article

VL - 56

SP - 1045

EP - 1052

JO - Applied Magnetic Resonance

JF - Applied Magnetic Resonance

SN - 0937-9347

IS - 8

M1 - 12

Y2 - 31 March 2025 through 4 April 2025

ER -