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Complex methods of physical and chemical analysis: differential thermal analysis (DTA), X-ray phase analysis (XRD), microstructural analysis (MSA), as well as density and microhardness measurements, were used to study the nature of chemical interaction in the Ho-Sb-Te ternary system over the entire concentration range along the following sections:1. Sb2Te3-Ho2Te3, 2. Sb2Te3-HoTe, 3. HoTe-Sb, 4. HoSb-HoTe, 5. Sb2Te3-Ho, 6. HoSb-Te. The projection of the liquidus surface of the ternary system and the diagrams of the state of internal sections were constructed according to experimental data and literature data on binary systems: Sb-Te, Sb-Ho, Ho-Te. It is established that sections (1), (2), (3), (4) are quasi-binary, and (5), (6) are non-quasi-binary sections of the ternary system. The incongruently melting compound HoSbTe3 is formed in the Sb2Te3-Ho2Te3 system and the area of solid solutions based on Sb2Te3 ~ 3-5 mol% at 300K was found. [ABSTRACT FROM AUTHOR]

The polycrystalline samples of the new ferroelectric ceramics ( 1 − x ) S r 3.35 B a 1.65 N b 10 O 30 (SBN) - ( x ) B a 4 N a 2 N b 10 O 30 (BNN) with potassium tungsten bronze structure were prepared using a high - temperature solid - state reaction technique. They are novel inorganic materials with potassium tungsten bronze structural type. The formation of the ceramics under the reported conditions has been confirmed by an X - ray diffraction technique. The ceramic microstructures were observed using scanning electron microscopy (SEM) techniques associated with energy dispersive X – ray spectroscopy (EDX) analysis. The SEM micrograph exhibits grain boundary distribution. Dielectric properties of the SBN - NBN compounds as a function of temperature (300–850 K) at frequencies 1–1000 KHz were studied. Detailed studies of variation of dielectric parameters with temperature and frequency confirmed the existence of ferroelectricity in these materials. The difference between the high - frequency dielectric constants and the low - frequency dielectric constants indicates that the ferroelectric phase transition in SBN - NBN compounds is of rather diffuse nature than relaxor type. According to the experimental data, it is suggested that ferroelectrics phase transition is a first - order transition. [ABSTRACT FROM AUTHOR]