Effect of Mn doping on the low-temperature synthesis of tricalcium phosphate (TCP) polymorphs

Effects of the full-scale substitution of strontium for calcium on the microstructure of brushite: (CaxSr1–x)HPO4.nH2O system

“…Calcium and strontium meet these two conditions, and thus the two ions can replace each other in a crystal (Rokita et al , 1993). The substitution of calcium by strontium in CaP phases such as hydroxylapatite (HA), amorphous CaP (ACP), octacalcium phosphate (OCP) and brushite has been investigated in the past (Sinusaite et al , 2019; Amjad et al , 2020; Wu et al , 2020). Various bone cements loaded with Sr have been introduced (Tadier et al , 2012; Schumacher & Gelinsky, 2015).…”

In Vitro Properties of Manganese-Substituted Tricalcium Phosphate Coatings for Titanium Biomedical Implants Deposited by Arc Plasma

“…This hypothesis can be supported by the ref. [ 27 ]. Authors [ 27 ] found that the increase of Mn concentration leads to the β-TCP phase formation, while α-TCP is formed at low Mn content.…”

“…Conventionally, the Mn 2+ -TCP systems are described by the spin-Hamiltonian ( Ĥ ) [ 30 ]: Ĥ = gβBS + D [ S 2 z − S ( S + 1)/3] + E ( S 2 x − S 2 y ) + ASI where S x , y , z are the projections of the electronic spin S = 5/2 on the principal direction of D ; D and E are the commonly used (axial and orthorhombic, correspondingly) parameters for ZFS; g and A are the isotropic g -factor and the hyperfine constant, respectively. In previous studies [ 27 , 31 ], it was shown for Mn-doped HA and TCP that g ≈ 2.001, D = 53(4) mT (1.5 GHz), Е = 14(3) mT (0.4 GHz), and A ≈ 9.4(4) mT. Our results ( Figure 3 ) can be satisfactorily described by g ≈ 2.003, D = 42(5) mT, Е = 9(2) mT, and A ≈ 9.5(5) mT.…”

“…However, EPR signals from integer spin systems can be detected when the oscillating magnetic field, applied to induce a spin-state transition, is oriented parallel to the B. The parallel magnetic field orientation allows transitions between the Ms = ±2 energy levels [ 27 ]. Indeed, in parallel mode, in the magnetic fields of less than 200 mT, a broad signal was detected in the Mn-TCP deposited coating ( Figure 5 ).…”

“…[27]. Authors [27] found that the increase of Mn concentration leads to the β-TCP phase formation, while α-TCP is formed at low Mn content. Mn content in the powder and in the coating was determined by the SEM-EDX analysis as 2.5 and 2.3 wt%, respectively.…”