Characterization of Cd implanted and annealed GaAs and InP by perturbed angular correlation (PAC) spectroscopy

Exploring solid state physics properties with radioactive isotopes

“…The results of the different techniques are interpreted as follows [117,118]: Already after annealing at 500 K nearly all Cd atoms are located on substitutional lattice sites, as demonstrated by EC. But PAC studies detect unperturbed, substitutional lattice sites for all Cd atoms only above 700 K. This is not a discrepancy but is due to the different sensitivities of the two techniques.…”

“…But a wider choice of suitable and interesting probe atoms now becomes available, particularly for the hyperfine technique PAC (e.g. 111m Cd, T 1/2 = 48 min; 77 Kr, T 1/2 = 74 min; 117 Cd, T 1/2 = 2.5 h) and EC (e.g. 24 Na, T 1/2 = 15 h, 107 Cd, T 1/2 = 6.5 h).…”

“…Some combinations of probe atoms and host lattices allow one to dope the samples directly via nuclear reactions inside the material. Typical examples are the doping of cadmium and cadmium compounds with 111 In via the 111 Cd(p, n) 111 In reaction [42] and with 117 Cd via the neutron capture reaction 116 Cd(n, γ ) 117 Cd [43] or the production of 77 Br in arsenic or arsenic compounds via the 75 As(α, 2n) 77 Br reaction [44]. However, research in nuclear solid state physics demands a much larger variety of possible combinations of probe atoms and host lattices.…”

“…First tested for ytterbium and lithium [50] it has recently been used successfully for the production of silver [51], manganese [52], beryllium [53], nickel [54] and copper [55,56] isotopes. Immediately, these achievements were exploited in MS, PAC, PL and EC experiments using the MS probe atom 57 Mn → 57 Fe [57], the PAC isotopes 117 Cd → 117 In (populated by the decay of 117 Ag) [58], 111 Ag → 111 Cd for PL [59,60] and 57 Mn → 57 Fe, 67 Cu and 111 Ag for EC studies [61].…”

“…450 K indicate that nearly all Cd atoms have been incorporated on substitutional lattice sites [63,116]. The same process was extensively investigated with PAC and HE measurements [117][118][119]. The PAC measurements revealed that at annealing temperatures below 500 K most of the probe atoms are exposed to a distribution of EFG caused by a variety of defects in the neighbourhood.…”