resumo
The impact of selective rare-earth (RE) additions in ZrO2-based ceramics on the resultant crystal structure, mechanical, morphological, optical, magnetic, and imaging contrast features for potential applications in biomedicine is explored. Six different RE, namely, Yb3+, Dy3+, Tb3+, Gd3+, Eu3+, and Nd3+ alongside their variations in the dopant concentrations were selected to accomplish a wide range of combinations. The experimental observations affirmed the roles of size and dopant concentration in determining the crystalline phase behavior of ZrO2. The significance of tetragonal ZrO2 (t-ZrO2) -> monoclinic ZrO2 degradation is evident with 10 mol % of RE substitution, while RE contents in the range of 20 and 40 mol % ensured either t-ZrO2 or cubic ZrO2 (c-ZrO2) stability until 1500 degrees C. High RE content in the range of 80-100 mol % still confirmed the structural stability of c-ZrO2 for lower-sized Yb3+, Dy3+, and Tb3+, while the c-ZrO2 -> RE2Zr2O7 phase transition becomes evident for higher-sized Gd3+, Eu3+, and Nd3+. A steady decline in the mechanical properties alongside a quenching effect experienced in the emission phenomena is apparent for high RE concentrations in ZrO2. On the one hand, the paramagnetic characteristics of Dy3+, Tb3+, Gd3+, and Nd3+ fetched excellent contrast features from magnetic resonance imaging analysis. On the other hand, Yb3+ and Dy3+ added systems exhibited good X-ray absorption coefficient values determined from computed tomography analysis.
palavras-chave
UP-CONVERSION LUMINESCENCE; LOW-TEMPERATURE DEGRADATION; TOUGHENED ALUMINA SYSTEMS; CONTRAST AGENTS; IN-VIVO; STABILIZED ZIRCONIA; ENERGY-TRANSFER; AGING BEHAVIOR; TRICALCIUM PHOSPHATE; OXIDE NANOPARTICLES
categoria
Materials Science
autores
Srigurunathan, K; Meenambal, R; Guleria, A; Kumar, D; Ferreira, JMD; Kannan, S
nossos autores
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)agradecimentos
The financial assistance received from Council of Scientific and Industrial Research, CSIR, India [Reference No. 01(2952)/18/EMR-II dated 01.05.2018], and Department of Science and Technology-Science and Engineering Research Board, DST-SERB, India [Reference No. EMR/2015/002200 dated 20.01.2016], are acknowledged. The facilities availed from Central Instrumentation Facility of Pondicherry Univ. are also acknowledged. K.S. acknowledges CSIR, India (Reference No. 09/559(0123)/18-EMR-I), for Senior Research Fellowship. The support from the Project CICECO-Aveiro Institute of Materials (Reference No. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement, is acknowledged.