We investigate the direct correspondence between Co band ferromagnetism and structural parameters in the pnictide oxides RCoPO for different rare-earth ions (R = La, Pr, Nd, Sm) by means of muon-spin spectroscopy and ab initio calculations, complementing our results published previously [G. Prando et al., Common effect of chemical and external pressures on the magnetic properties of RCoPO (R = La, Pr), Phys. Rev. B 87, 064401 (2013)]. We find that both the transition temperature to the ferromagnetic phase TC and the volume of the crystallographic unit cell V are conveniently tuned by the R ionic radius and/or external pressure. We report a linear correlation between TC and V and our ab initio calculations unambiguously demonstrate a full equivalence of chemical and external pressures. As such, we show that R ions influence the ferromagnetic phase only via the induced structural shrinkage without involving any active role from the electronic f degrees of freedom, which are only giving a sizable magnetic contribution at much lower temperatures.
Prando, G., Profeta, G., Continenza, A., Khasanov, R., Pal, A., Awana, V.P.S., et al. (2015). Common effect of chemical and external pressures on the magnetic properties ofRCoPO (R=La,Pr,Nd,Sm). II. PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS, 92(14), 1-9 [10.1103/PhysRevB.92.144414].
Common effect of chemical and external pressures on the magnetic properties ofRCoPO (R=La,Pr,Nd,Sm). II
SANNA, SAMUELE
2015
Abstract
We investigate the direct correspondence between Co band ferromagnetism and structural parameters in the pnictide oxides RCoPO for different rare-earth ions (R = La, Pr, Nd, Sm) by means of muon-spin spectroscopy and ab initio calculations, complementing our results published previously [G. Prando et al., Common effect of chemical and external pressures on the magnetic properties of RCoPO (R = La, Pr), Phys. Rev. B 87, 064401 (2013)]. We find that both the transition temperature to the ferromagnetic phase TC and the volume of the crystallographic unit cell V are conveniently tuned by the R ionic radius and/or external pressure. We report a linear correlation between TC and V and our ab initio calculations unambiguously demonstrate a full equivalence of chemical and external pressures. As such, we show that R ions influence the ferromagnetic phase only via the induced structural shrinkage without involving any active role from the electronic f degrees of freedom, which are only giving a sizable magnetic contribution at much lower temperatures.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.