Gadolinium-doped strontium titanate for high-efficiency electromagnetic interference shielding

CoFe2O4 nanoparticles decorated MoS2-reduced graphene oxide nanocomposite for improved microwave absorption and shielding performance

“…[6][7][8] Therefore, in the past few years, considerable effort has been devoted to designing and fabricating ideal high-performance microwave absorption (MA) and EMI shielding materials, which signicantly mitigate the increasing problem of serious EMI. 7,9 An ideal EM wave absorbing and shielding material can be widely used in electronic device protection, environmental pollution cleaning, wireless telecommunication, and in human health care, for example. These materials exhibit many essential properties, such as a low density, light weight, thinness, high electrical conductivity, large surface area, wide absorption efficiency range, and good thermal and chemical stability.…”

Local and electronic structure of Sr1-Gd TiO3 probed by X-ray absorption spectroscopy

“…Specifically, Gd 3+ ion substitutes Sr 2+ ion and 1/2 strontium vacancy (VSr) is formed via charge compensation effect. These vacancies are believed to break the translational symmetry of the lattice and represent a type of disorder associated with the formation of polar regions in the material [23]. Another mechanism of charge compensation is the formation of oxygen interstitial (Oi) when oxygen vacancies are presented.…”

“…Another mechanism of charge compensation is the formation of oxygen interstitial (Oi) when oxygen vacancies are presented. In this case, Gd 3+ ion substitutes Sr 2+ ion and 1/2 Oi is formed [23]. Notably, the polymeric precursor method is a preparation process of oxides in which oxygen vacancies are common formed as a result of the synthesis and subsequent heat treatment [38].…”

“…Besides, due to the larger mass of Gd than that of Sr, Gd-doping would effectively lower the thermal conductivity of the STO due to a larger mass fluctuation effect that enhances the phonon scattering processes [20], corresponding to a higher thermoelectrical performance [21]. It was also shown that the proper amount of Gd-doping leads to an insulator-metal transition in STO [22], what would allow, for instance, its application as an electromagnetic interference shielding [23]. Even more, once the Gd 3+ crystal radius (1.41 Å) is smaller as compared to that for the Sr 2+ (1.58 Å), the Gd 3+ will occupy off-center positions in the STO structure, inducing an elastic lattice strain that suppress the intrinsic quantum fluctuation that hinders the observation of any ferroelectric phase transition [24,25].…”

High-efficiency and ultra-thin electromagnetic wave absorption xAl2O3–(1 − x)Sr0.85Gd0.15TiO3 ceramics in X-band

“…For example, when SrTiO 3 was doped with rare earth elements, a vast number of defects and oxygen vacancies came forth [18]. The suitable substitution (La 3+ /Gd 3+ in Sr 2+ site) can effectively change the carrier concentration of SrTiO 3 and microwave dielectric properties [18][19][20].…”