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.	Experiment	Constant parameter	Changing parameter	Results
1	Variation of pH	Upper 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 concentration	Upper 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.
3	Variation of gel ageing	Upper 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.
4	Variation of upper reactant concentration	Lower 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.