Structural and electro-magnetic properties of Na2O-BaO-Al2O3-P2O5 glasses doped with CdO for sensors and magnetic storage devices

The role of CdO additions on the structural, magnetic, and electrical properties of the amorphous 20Na₂O-25BaO-(15-x)Al₂O₃ -xCdO-40P₂O₅ (mol%) glasses with (0.0 $\le x\le$ 15.0 mol%) has been investigated. The prepared glasses were characterized by using XRD, FTIR, and VSM approaches. The FTIR spectra revealed the presence of various structural groups with the forming of P-O-Cd bonds. Embedding the studied glass with CdO enhances its magnetic characteristics in an overlapping magnetic field. Furthermore, the Ac conductivity (${\sigma }_{ac}$) and complex dielectric constant (real and imaginary) were studied at the 50–500 kHz range of frequency and 300–370 K temperature. The frequency dependence of ${\sigma }_{ac}$ is successfully described by the Almond-West formula relationship. The fitting parameters ${\sigma }_{dc},{\omega }_{hf},\text{and}$ n have been precisely estimated. Values of ${\sigma }_{ac}$ has been increasing with the increase of temperature and/or frequency. This would be expected due to CdO additions leading to a network made up of P₂O₅ and Al₂O₃ that may be broken up by CdO, forming non-bridging oxygens that make ion transport simpler. The values of the activation energies for $E_{ac}$, $E_{dc}$, and $W_M$ are found to decrease with increasing CdO content. This evidence affirms that as Na⁺ (and Ba²⁺) ions require less activation energy to hop between non-bridging oxygen sites, the ionic conductivity increases. As a result, these glasses can serve as solid electrolytes in batteries or fuel cells, facilitating ion transport. Both the complex dielectric constant (real, ${\epsilon }_1\text{,}$ and imaginary, ${\epsilon }_2\text{,}$), dielectric loss, $\tan \left(\delta \right)\text{,}$ and material capacity, C_p have been estimated and well discussed. These parameters increase with increasing CdO or temperatures. Due to the responsive nature of these glasses to change in frequency and temperature make them suitable for sensor applications. This in turn enables these glasses to be used in defense applications such as remote chemical warfare sensors, thermal sensors in infrared vision systems, and radiation sensors in nuclear safety which agrees with the 2030 vision of King Saudi Arabia.