Spin–lattice relaxations of paramagnetic Fe³⁺in ZnO

Atomic‐Scale Magnetic Properties of Truly 3d‐Diluted ZnO

“…[ 28 ] Employing eMS, spin relaxation rates in the range of τ −1 ≈ 4 × 10 6 -1 × 10 8 Hz can be extracted from the temperature-dependent broadening of the magnetically-split sextets. [ 20,21 ] This sensitivity range is correlated with the mean lifetime ( τ M = 140 ns) of the 14.4 keV 57 Fe Mössbauer state. The spin relaxation rates were obtained for the set of ZnO samples under study as a function of the Fe 3+ concentration and are shown in Figure 3 .…”

“…The dashed line shows a comparison with a square dependence on the Fe 3+ concentration. the Fe 3+ spin-lattice relaxation rate at RT is extrapolated to be ≈10 5 Hz, [ 21 ] which is far below the detection limit in eMS. This also leads to the conclusion that the main contribution to the broadening of the Fe 3+ magnetically-split sextet components at RT (Figure 1 ) is due to spin-spin type of relaxation.…”

“…The eMS spectra were analyzed in terms of four components: (1) Fe C attributed to Fe 2+ on substitutional Zn sites; [ 12,14 ] (2) Fe I attributed to recoil-produced (and/or as-implanted) interstitial Fe, [ 9 ] not observed in 57 Co implantation; [ 14 ] (3) magnetically-split component Fe(III), attributed to Fe 3+ on substitutional Zn sites [ 13,15 ] analyzed in terms of the empirical relaxation model based on the Blume and Tjon lineshape (EmpBT) developed by Mølholt et al; [ 20,21 ] [ 14 ] Fe C and Fe I were analyzed with asymmetric doublets taking into account the emission angle relative to the crystal a) Implantations at 60 keV at RT, performed at 0° relative to the sample normal; b) Implantations performed at 30° relative to the sample normal; c) Calculated from an integration of the implantation/measurement profi les as determined from TRIM calculations. [ 19 ] The convolution considers the ion mass and the implantation energy and angle;…”

“…For pure ZnO (total Mn/Fe concentration <10 −4 at%), [ 20,21 ] as a function of average Fe 3+ concentration. The dashed line shows a comparison with a square dependence on the Fe 3+ concentration.…”

5 7 Fe Emission Mössbauer Study on Gd 3 Ga 5 O 1 2 implanted with dilute 5 7 Mn

“…It is of interest to note, that despite the extreme dilution used, sextet-like spectral components due to slow paramagnetic relaxation of Fe 3+ are not observed as in similar eMS experiments in other oxides [8][9][10][11]. Instead high-spin Fe 3+ (Fe 3+ on Ga T sites, DB3) show fast (>10 10 Hz) spin relaxation and is observed as a doublet.…”