Indian Journal of Materials Science / 2014 / Article / Tab 1

Research Article

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

Table 1

Summary of growth experiments based on variation of gel pH, dopant concentration, and gel ageing time in case of samarium doped calcium hydrogen phosphate (Sm:CHPD) crystals at a constant gel density of 1.04 g/cc.

S. No.ExperimentConstant parameterChanging parameterResults

1Variation of pHUpper reactant conc. (1 M); lower reactant conc. (0.5 M); gel conc. (0.5 M).Gel pH (4, 5, 6, 7)(1)  Morphology
Single crystal, needle, thin platelets, blade shaped.
(2) Nucleation density
Minimum for pH 7 and maximum for pH 5.
(3) pH value 4 is not conducive for crystal growth.
(4) Liesegang ring formation at pH 5 and 7.

2 Variation of dopant concentrationUpper reactant conc. (1 M); lower reactant conc. (0.5 M); gel conc. (0.5 M); gel ageing time-72 h; gel pH 5.Dopant concentration (10% and 20%)(1) Morphology
Single crystal, needle, thin platelets, blade shaped.
(2) Nucleation density
Minimum for 10% and maximum for 20%.
(3) Crystallization at all doping concentration.

3Variation of gel ageingUpper reactant conc. (1 M); lower reactant conc. (0.5 M); gel conc. (0.5 M); gel pH 5.Gel ageing (24 h, 48 h, 72 h, 96 h, 120 h) (1) Morphology
Single crystal, needle, thin platelets, blade shaped.
(2) Nucleation density
Minimum for 120 h and maximum for 24 h.
(3) Crystallization at all ages.

4Variation of upper reactant concentrationLower reactant conc. (0.5 M); gel conc. (0.5 M); gel pH 5; gel ageing (72 h).Upper reactant concentration (0.5 M and 1 M)(1) Morphology
Single crystal, needle, thin platelets, blade shaped.
(2) Nucleation density
Minimum for 0.5 M and maximum for 1 M of upper reactant concentration.
(3) Crystals nucleate at all upper reactant concentrations.