Electric and magnetic properties of titanium-cobalt-oxide single crystals produced by floating zone melting with light heating

• Дата: 2017
• Автори: Balbashov, A.M., Mukhin, A.A., Ivanov, V.Y., Iskhakova, L.D., Voronchikhina, M.E.
• Формат: Стаття
• Мова: English
• Опубліковано: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2017
• Назва видання: Физика низких температур
• Теми: Low dimensionality and inhomogeneity effects in quantum matter
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/175126
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Electric and magnetic properties of titanium-cobalt-oxide single crystals produced by floating zone melting with light heating / A.M. Balbashov, A.A. Balbashov, V.Y. Ivanov, L.D. Iskhakova, M.E. Voronchikhina // Физика низких температур. — 2017. — Т. 43, № 8. — С. 1200-1206. — Бібліогр.: 12 назв. — англ.

Single crystals of spinel Co₂TiO₄, CoTiO₃ of ilmenite structure and pseudobrookite CoTi₂O₅ were grown by means of zone melting equipment URN-2-ZM. The growth processes were performed in an air atmosphere with a speed ∼10 mm/h and a final annealing of the crystal at temperature of 1250 °C. Co₂TiO₄ and CoTi₂O₅ crystals were obtained with a diameter of 12–15 mm and length up to 60 mm, being free of any other phase inclusions and cracks. However, in the CoTiO₃ crystals some controversial features were found: x-ray Laue analysis indicated high-structure perfection while an electronic microscopy revealed small amount of second phase inclusions in contradiction to known phase diagram of this system. Electrical and magnetic properties of grown Co₂TiO₄ and CoTiO₃ single crystals were studied. Semiconducting behavior of the Co₂TiO₄ was established with the energy gap of ∼1.3 eV. No magnetic anisotropy was found in the cubic Co₂TiO₄ single crystals showing a magnetic behavior similar to polycrystals. The rhombohedral CoTiO₃ crystals revealed a magnetic behavior of an easy plane antiferromagnet with a significant anisotropy of the transverse magnetic susceptibilities along and perpendicular to the trigonal c axis.