Dielectric relaxation and AC conductivity studies of Se₉₀Cd_10−xIn_x glassy alloys

Peer review under responsibility of The Ceramic Society of Japan and the Korean Ceramic Society.

Figures & data

Table 1 Glass transition (T_g) and crystallization temperatures (T_c) for glassy Se₉₀Cd_10−xIn_x (x = 2, 4, 6, 8) alloys.

Sample Se90Cd10−xInx	Tg (°C)	Tc (°C)
x = 2	120	218
x = 4	126	219
x = 6	128	220
x = 8	130	224

Fig. 1 DSC thermograms for glassy Se₉₀Cd_10−xIn_x (x = 2, 4, 6, 8) alloys at heating rate of 10 K min⁻¹.

Fig. 2 SEM images of Se₉₀Cd_10−xIn_x glassy alloys at 10,000× magnification [(a) x = 2, (b) x = 4, (c) x = 6 and (d) x = 8].

Table 2 The compositional analysis of Se₉₀Cd_10−xIn_x (x = 2, 4, 6, 8) glassy alloys.

Sample Se90Cd10−xInx	Weight%				Atomic%
	Se	Cd	In	Total	Se	Cd	In	Total
x = 2	88.80	6.96	4.24	100	91.92	5.06	3.02	100
x = 4	75.47	12.47	12.07	100	81.57	9.46	8.97	100
x = 6	89.60	4.11	6.28	100	92.55	2.98	4.46	100
x = 8	85.38	3.03	11.59	100	89.42	2.23	8.35	100

Fig. 3 Energy dispersive X-ray analysis EDAX for Se₉₀Cd₈In₂ glassy alloy.

Table 3 Dielectric constant (ɛ′) and Dielectric loss factor (ɛ″) for Se₉₀Cd_10−xIn_x (x = 2, 4, 6, 8) alloys at selected frequencies.

Sample Se90Cd10−xInx	Dielectric constant (ɛ′)		Dielectric loss factor (ɛ″)
	500 Hz, 300 K	1 kHz, 300 K	500 Hz, 300 K	1 kHz, 300 K
x = 2	6.66 × 10^4	2.96 × 10^4	5.51 × 10^4	2.45 × 10^4
x = 4	3.24 × 10^4	9.61 × 10^3	3.94 × 10^4	1.65 × 10^4
x = 6	2.05 × 10^4	9.32 × 10^3	3.62 × 10^4	1.64 × 10^4
x = 8	1.57 × 10^4	9.25 × 10^3	1.21 × 10^4	3.13 × 10^3

Fig. 4 Variation of real part of dielectric constant with log f.

Fig. 5 Variation of dielectric loss with log f.

Table 4 Calculated covalent character of bonds for Se₉₀Cd_10−xIn_x (x = 2, 4, 6, 8) glassy alloys.

Bond type	Covalent character
Se–Se	100
Se–Cd	81.56
Se–In	86.30
Cd–Cd	100
Cd–In	99.55
In–In	100

Fig. 6 Compositional dependence of dielectric constant (ɛ′) in Se₉₀Cd_10−xIn_x glassy alloys.

Fig. 7 Compositional dependence of dielectric loss (ɛ″) in Se₉₀Cd_10−xIn_x glassy alloys.

Fig. 8 Variation of loss angle Tan δ with frequency for Se₉₀Cd_10−xIn_x at room temperature for different compositions.

Fig. 9 Variation of AC conductivity with log f.

Table 5 Values of AC conductivity σ_ac(ω) for Se₉₀Cd_10−xIn_x (x = 2, 4, 6, 8) alloys at room temperature.

Sample Se90Cd10−xInx	Frequency f = 1 kHz	Frequency f = 10 kHz	Frequency f = 100 kHz
	σac(ω)	σac(ω)	σac(ω)
x = 2	1.39 × 10^−3	2.18 × 10^−3	6.84 × 10^−3
x = 4	8.62 × 10^−4	1.81 × 10^−3	6.33 × 10^−3
x = 6	8.35 × 10^−4	1.56 × 10^−3	5.69 × 10^−3
x = 8	8.10 × 10^−4	1.45 × 10^−3	5.29 × 10^−3

Fig. 10 Cole–Cole plot of Se₉₀Cd_10−xIn_x glassy alloys: (a) x = 2, (b) x = 4, (c) x = 6 and (d) x = 8.

Table 6 Bulk resistance (R_b) of Se₉₀Cd_10−xIn_x (x = 2, 4, 6, 8) glassy alloys.

Sample Se90Cd10−xInx	Rb (kΩ)
x = 2	300
x = 4	325
x = 6	330
x = 8	340