TY  - JOUR
AU  - Sewak, Ram
AU  - Dey, Chandi Charan
AU  - Toprek, Dragan
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10638
AB  - Temperature dependent phase transformation behavior in cobalt from hexagonal close-packed (hcp) to face centered cubic (fcc) has been found to be contradictory to that reported earlier. It is found that hcp phase stabilizes at both low and high temperature ($$\sim $$873 K) while fcc phase is stabilized at $$\sim $$500 K. At 298 K, hcp Co has been found to be predominant ($$\sim $$70%) where hcp magnetic phase is $$\sim $$60%. At 973 K, hcp phase is again predominant ($$\sim $$73%), but it is mainly the non-magnetic phase ($$\sim $$67%). Contrary to present results, it was found earlier that fcc phase was stabilized at high temperature and hcp to fcc transformation occured at $$\sim $$700 K. Present results from perturbed angular correlation measurements, therefore, requires a new theoretical interpretation for Co phase transformation. From present measurements, hyperfine magnetic fields in Co at room temperature for the hcp and fcc phases have been found to be 18.7(6) and 12.8(3) T, much lower than earlier reported results. The hyperfine magnetic fields at $$^{181}$$Ta impurity atom have been calculated by density functional theory (DFT) employing the full potential (linearized) augmented plane wave method (FP-LAPW). Present calculated results for both hcp and fcc phases corroborate our experimental results.
T2  - Scientific Reports
T1  - Temperature induced phase transformation in Co
VL  - 12
IS  - 1
SP  - 10054
DO  - 10.1038/s41598-022-14302-x
ER  - 

@article{
author = "Sewak, Ram and Dey, Chandi Charan and Toprek, Dragan",
year = "2022",
abstract = "Temperature dependent phase transformation behavior in cobalt from hexagonal close-packed (hcp) to face centered cubic (fcc) has been found to be contradictory to that reported earlier. It is found that hcp phase stabilizes at both low and high temperature ($$\sim $$873 K) while fcc phase is stabilized at $$\sim $$500 K. At 298 K, hcp Co has been found to be predominant ($$\sim $$70%) where hcp magnetic phase is $$\sim $$60%. At 973 K, hcp phase is again predominant ($$\sim $$73%), but it is mainly the non-magnetic phase ($$\sim $$67%). Contrary to present results, it was found earlier that fcc phase was stabilized at high temperature and hcp to fcc transformation occured at $$\sim $$700 K. Present results from perturbed angular correlation measurements, therefore, requires a new theoretical interpretation for Co phase transformation. From present measurements, hyperfine magnetic fields in Co at room temperature for the hcp and fcc phases have been found to be 18.7(6) and 12.8(3) T, much lower than earlier reported results. The hyperfine magnetic fields at $$^{181}$$Ta impurity atom have been calculated by density functional theory (DFT) employing the full potential (linearized) augmented plane wave method (FP-LAPW). Present calculated results for both hcp and fcc phases corroborate our experimental results.",
journal = "Scientific Reports",
title = "Temperature induced phase transformation in Co",
volume = "12",
number = "1",
pages = "10054",
doi = "10.1038/s41598-022-14302-x"
}

Sewak, R., Dey, C. C.,& Toprek, D.. (2022). Temperature induced phase transformation in Co. in Scientific Reports, 12(1), 10054.
https://doi.org/10.1038/s41598-022-14302-x

Sewak R, Dey CC, Toprek D. Temperature induced phase transformation in Co. in Scientific Reports. 2022;12(1):10054.
doi:10.1038/s41598-022-14302-x .

Sewak, Ram, Dey, Chandi Charan, Toprek, Dragan, "Temperature induced phase transformation in Co" in Scientific Reports, 12, no. 1 (2022):10054,
https://doi.org/10.1038/s41598-022-14302-x . .