Influence of postdeposition annealing on structural properties and electrical characteristics of thin Tm2O3 and Tm2Ti2O7 dielectrics

Thermo-selective TmxTi1−xO2−x/2nanoparticles: from Tm-doped anatase TiO2to a rutile/pyrochlore Tm2Ti2O7mixture. An experimental and theoretical study with a photocatalytic application

“…In turn, the patterns obtained showed that anatase was the predominant phase in the samples annealed at 773 and 973 K in most cases, while rutile was the predominant phase in the samples annealed at 1173 K. So, the Tm 3+ ion may have been incorporated into the anatase structure but not the rutile one, probably because the ionic radius of Tm 3+ is considerably larger than that of Ti 4+ (r(Ti 4+ ) = 0.68 Å; r(Tm 3+ ) = 0.994 Å), 28 and the anatase structure is less dense than the rutile one. Moreover, Shlyakhtina et al reported fluorite-pyrochlore-fluorite phase transitions for Ln 2 Ti 2 O 7 (Ln = Lu, Yb, Tm), and that the pyrochlore structure is formed at T > 1073 K. 26 Typically, pyrochlore compounds (based on rare earths, that is, Ln 2 Ti 2 O 7 ) are obtained by solidstate reactions at elevated temperatures, 25,29 rf cosputtering deposition, 30,31 and hydroxide coprecipitation followed by freeze-drying. 26,32 In our case, the pyrochlore structure Tm 2 Ti 2 O 7 was obtained using a solution-based method of synthesis.…”

Single crystalline Tm2O3 films grown on Si (001) by atomic oxygen assisted molecular beam epitaxy

“…Because of its high dielectric constant, wide band gap and predicted chemical and thermal stability on Si, thulium oxide (Tm 2 O 3 ) may also be a promising candidate as a suitable gate dielectric layer in CMOS device materials [6][7][8]. However, only a few papers on Tm 2 O 3 as a gate dielectric have been published [9,10]. Paivasaari et al [9] reported on a Tm 2 O 3 film with a k value of 9.4, which was grown on Si (1 0 0) substrate by atomic layer deposition and had a polycrystalline structure without preferential orientations.…”

“…Paivasaari et al [9] reported on a Tm 2 O 3 film with a k value of 9.4, which was grown on Si (1 0 0) substrate by atomic layer deposition and had a polycrystalline structure without preferential orientations. Pan and Yen [10] reported on a Tm 2 O 3 film that was deposited by reactive sputtering and was amorphous in structure. After rapid thermal annealing (RTA) at 700 1C in O 2 ambient, the film became polycrystalline.…”