Preparation of Samarium Doped Calcium Hydrogen Phosphate and Study of Its Density and Thermal and Dielectric Characteristics

K K Bamzai,Goldy Slathia,Shivani Suri,Vishal Singh,Seema Verma,Rashmi Gupta,Bindu Raina

doi:10.1155/2014/609463

Abstract

Samarium doped calcium hydrogen phosphate was synthesized as single crystal by room temperature solution growth technique, namely, silica gel technique. The kinetics of the growth parameters was studied with regard to variation of pH, dopant concentration, gel ageing, and upper reactant concentration. The optimum conditions for the growth of good quality single crystal were worked out. Single crystal X-ray diffraction analysis establishes that the crystal belongs to monoclinic system. The density observed by the flotation method is greater than the density of the reported pure calcium hydrogen phosphate thereby suggesting the incorporation of the dopant (Sm) ion into the lattice of host (CHP). Thermal analysis gave two sharp endothermic peaks which are due to partial dehydration and phase transition, respectively. Dielectric studies establish a shift in the Curie temperature from 355 to 370°C only at higher frequencies thereby suggesting the relaxational behavior of the material.

Highlights

Rare earth phosphate crystals are interesting materials as they find wide technological applications on account of their ferroelectric, piezoelectric, optical, and other important properties whereas phosphoric acid serves as the base for the development of new class of materials
Brushite phase precipitates most readily in urine environments at pH less than 6.9, so it has been postulated that Brushite enables the nucleation of calcium oxalate monohydrate (COM), the major component of kidney stones [5]
(ii) Single crystal X-ray diffraction results reveal that the grown crystals have monoclinic system with lattice parameters: a = 6.3554(9) A, b = 15.1526(13) A, c = 5.8098(6) A, α = 90∘, β = 118.55∘, and γ = 90∘ with volume V = 491.454 (A )3 and space group C2/c

Summary

Introduction

Rare earth phosphate crystals are interesting materials as they find wide technological applications on account of their ferroelectric, piezoelectric, optical, and other important properties whereas phosphoric acid serves as the base for the development of new class of materials. Recent studies used it as a precursor to form apatite [Ca10(PO4)6(OH)2], an important bone forming mineral, as it contains 23% calcium in its anhydrous form. Brushite mineral has been found under various pathological conditions including kidney stones and some forms of arthritis [2, 3]. It was reported that the mineral deposits in the kidney contain various phases of calcium salts such as calcium oxalate and calcium phosphate [4]. Calcium phosphate minerals are thought to be the initiator of stone formation in the kidney and/or bladder under favorable physiological environment. Brushite phase precipitates most readily in urine environments at pH less than 6.9, so it has been postulated that Brushite enables the nucleation of calcium oxalate monohydrate (COM), the major component of kidney stones [5]

Methods

Results

Conclusion