Microwave dielectric properties of layered perovskite A2B2O7 single-crystal fibers

Crystal growth of spin-ice pyrochlores by the floating-zone method

“…Large single crystals of La 2 Ti 2 O 7 were first grown using the floating-zone technique and reported to be piezoelectric [1]. Other groups have grown this material in the form of fibers by laser-heated pedestal growth (LHPG) [5]. Later a range of rare-earth titanates have been grown by the optical floating-zone technique [6].…”

Electronic structure of layered titanate Nd2Ti2O7

“…Because of eight different sites for Nd 3+ ions, eight sites for Ti 4+ ions and considerable variations of Nd-O and Ti-O distances in the crystal lattice, Nd 2 Ti 2 O 7 shows a great potential for solid solution formation with possible substitution in Nd or Ti positions. As to physical properties, Nd 2 Ti 2 O 7 is characterized by an extremely high Curie temperature T C > 1500°C, spontaneous polarization P s = 9 lC/cm 2 , high permittivity e = 31-47 [1,[3][4][5] and high piezoelectric properties [1,6] that holds promises for using this compound for the manufacture of ferroelectric random access memory (FRAM) elements [7][8][9][10][11]. Thermal stability up to T$1400°C and low dielectric losses open the way for a wide use of NTO as a key component in the fabrication of microwave ceramics and nanocomposites [12][13][14][15][16][17][18][19][20][21][22].…”

Thin Film Synthesis and Structural Characterization of a New Kinetically Preferred Polymorph in the RE2Ti2O7 (RE = La−Y) Family

“…13,14,28,29 The (110)-layered perovskites are important materials with a range of useful properties, including ferroelectricity, second harmonic generation, and photocatalytic activity. [30][31][32][33][34][35] The pyrochlore compounds are generally used as dielectrics, solid electrolytes, and refractory materials. 14,[36][37][38] The different rare earth titanates have been synthesized in their bulk stable form using a variety of synthesis techniques.…”

“…RE 2 Ti 2 O 7 compounds are known to exist as two different polymorphs in the bulk: the pyrochlore and the (110)-LP phase, depending on the rare earth cation. , The larger rare earth titanates, RE = La or Nd, are stable in the (110)-layered perovskite structure, while the smaller rare earth titanates, RE = Sm−Y, are stable in the pyrochlore structure. ,,, The (110)-layered perovskites are important materials with a range of useful properties, including ferroelectricity, second harmonic generation, and photocatalytic activity. − The pyrochlore compounds are generally used as dielectrics, solid electrolytes, and refractory materials. ,− The different rare earth titanates have been synthesized in their bulk stable form using a variety of synthesis techniques. ,− …”