**RE2O3 Nanoparticles Embedded in SiO2 Glass Matrix — A Colossal Dielectric and Magnetodielectric Response**

S. Mukherjee, T. H. Kao, H. C. Wu, K. Devi Chandrasekhar and H. D. Yang

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/60677

### **Abstract**

Significant experimental effort has been inspected to consider and implement favorable high-*k* gate dielectrics with magnetodielectric (MD) effect of series of rare earth oxide (RE2O3, RE ~ rare earth ions) nanoparticles (NPs) embedded in sol–gel derived SiO2 glass matrix. Properly calcined RE2O3 NP-glass composite systems (in which RE ~ Sm, Gd and Er) show an intriguing colossal enhancement of dielectric constant along with MD effect near room temperature. The enhancement of dielectric constant is closely related to oxygen vacancy induced dielectric relaxation (or, more correctly, particle size effect from different calcined temperature), reconstructed from extended X-ray absorption fine structure. The MD response is strongly depended on the superparamagnetic property of the rare earth ions. From application point of view, the enhancement of dielectric constant associated with MD response can be achieved by tuning the NPs size through varying annealing temperature and/or increasing the doping concentration of magnetic rare earth oxide, which will be the key guidelines to accomplish the compatibility, performance and reliability requirements for future complementary metal-oxide-semiconductor (CMOS) technology.

**Keywords:** Rare earth oxide nanoparticle, high-*k* materials, magnetodielectric effect, diffuse phase transition
