The dielectric spectrum of erbium doped CaF₂

Charge compensating defects study of YbF‐doped BaF crystals using dielectric loss

“…The dielectric measurements were performed using a RLC Meter ZM 2355 NF Corporation, Japan, over a temperature range 150-320 K, with a linear heating rate of 2 K min −1 , at nine audio-frequencies: 1,4,8,10,15,20,40,60, and 100 kHz. The real part of the dielectric constant, ε 1 , was calculated from the measured capacitance.…”

“…Figure 10 shows the influence of YbF 3 concentration on the NNN dipoles number. As the YbF 3 concentration increases the number of dipoles that effectively contribute to the dielectric loss peak increases linearly, unlike the NN dipoles in CaF 2 :YbF 3 [18] and CaF 2 :ErF 3 [10] that decrease.…”

“…The dielectric loss method allows an exact determination of the activation energy E and of the pre-exponential factor τ 0 of the Arrhenius relation. Since the imaginary part (ε 2 ) of the complex dielectric constant has a maximum for ωτ = 1 [8,10], it follows that:…”

“…The number of dipoles N D that contribute to the dielectric relaxation peak can be calculated from the dielectric spectra using various methods described in [10,21]. We used the method of Campos [21] that consists of plotting (T tan δ) versus 1000/T , where T is the temperature and tan δ is the dielectric loss.…”

Electrical Study of Pr3+ Ion Environment in Ca1?xPrxF2+x Thin Films

“…In CaF 2 : Er 3 bulk single crystals and relatively low erbium concentration (<0.10 mol%), extended X-ray-absorption fine structure [27,28], optical [29,30] and electrical [13,31] studies have shown that isolated nn, nnn and cubic Er 3 ±F À i single pairs, but also small (dimer, trimer) and large (pentamer, hexamer) clusters can coexist. In Ca 1Àx Er x F 2x thin films epitaxially grown on Si(100), we have previously shown that the number of these situations is reduced [32 to 34].…”