NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2017, 8 (4), P. 535–539
Phase transitions in nanostructured K1-x(NH4)(x)H2PO4 (x = 0 – 0.15) solid solutions
P.Yu. Vanina – Peter the Great Saint Petersburg Polytechnic University, Polytechnicheskaya, 29, St. Petersburg, 195251, Russia; p.yu.vanina@gmail.com
A. A. Naberezhnov – Ioffe Institute, Polytechnicheskaya, 26, St. Petersburg, 194021, Russia; alex.nabereznov@mail.ioffe.ru
O. A. Alekseeva – Peter the Great Saint Petersburg Polytechnic University, Polytechnicheskaya, 29, St. Petersburg, 195251, Russia; blackhole2010@yandex.ru
A. A. Sysoeva – Ioffe Institute, Polytechnicheskaya, 26, St. Petersburg, 194021, Russia; annasysoeva07@mail.ru
D. P. Danilovich – Engineering center of St. Petersburg State Technological Institute, Moskovsky prospect, 26, St. Petersburg, 190013, Russia; dmitrydanilovich@gmail.com
V. I. Nizhankovskii – International Laboratory of High Magnetic Fields and Low Temperatures, Gajowicka, 95, Wroclaw, 53421, Poland; nizhan@ml.pan.wroc.pl
Effect of ammonium dihydrogen phosphate admixture on phase transitions in nanostructured solid solutions (1-x)KH2PO4–(x)(NH4)H2PO4 at x = 0, 0.05 and 0.15 has been studied by dielectric spectroscopy. The samples have been prepared by embedding of aqueous solutions into porous borosilicate glasses. The X-ray diffraction have shown that the crystal structure at room temperature corresponds to the bulk KDP and the average nanoparticle diameters are 49 (2) nm for the sample with 5 % of (NH4)H2PO4 (ADP) and 46 (2) nm for the nanocomposites with 15 % of ADP. Dielectric response data analysis have revealed the shifts of the ferroelectric phase transition temperature as a function of (NH4)H2PO4 concentration: at x = 0 ΔTC is equal to ~6 K, at x = 0.05 ΔTC~3 K and at x = 0.15 ΔTC~2 K.
Keywords: ferroelectrics, antiferroelectrics, phase transitions, nanocomposite materials.
PACS 77.84.Fa; 68.65.-k; 68.35.Rh; 67.30.ht
DOI 10.17586/2220-8054-2017-8-4-535-539