Title :
Submillimeter dynamics of the new spin-reorientation in HoFe1-xAlxO3 induced by magnetic vacancies
Author :
Kozlov, G.V. ; Lebedev, S.P. ; Mukhin, A.A. ; Fedorov, I.V. ; Prokhorov, A.S. ; Balbashov, A.M. ; Parsegov, I.Yu.
Author_Institution :
Inst. of Gen. Phys., Acad. of Sci., Moscow, Russia
fDate :
11/1/1993 12:00:00 AM
Abstract :
Spin excitations in HoFe1-xAlxO3 orthoferrites involving Al impurity ions (magnetic vacancies) have been investigated at submillimeter wavelengths (v=2-25 cm-1 ). Three resonance modes are detected, two of which are identified as antiferromagnetic resonance modes in the Fe-subsystem, and the third as a rare-earth mode induced by electron transitions inside the ground quasidoublet of the Ho3+ ion. The observed temperature dependences and anomalies in the behavior of these modes at point T M=60 K indicate that in HoFe1-xAlxO3 there is a new first-order spin-reorientation phase transition (SRPT) from the weak ferromagnetic phase Γ4(FzGx), to the antiferromagnetic one Γ1(Gy), which is induced by the magnetic vacancies
Keywords :
antiferromagnetic properties of substances; antiferromagnetic resonance; ferrites; holmium compounds; spin dynamics; weak ferromagnetism; 2 to 25 cm-1; HoFe1-xAlxO3; antiferromagnetic resonance modes; electron transitions; first-order phase transition; ground quasidoublet; impurity ions; magnetic vacancies; orthoferrites; rare-earth mode; resonance modes; spin excitations; spin-reorientation; submillimeter dynamics; temperature dependences; weak ferromagnetic phase; Anisotropic magnetoresistance; Antiferromagnetic materials; Impurities; Magnetic anisotropy; Magnetic resonance; Magnetostriction; Oscillators; Perpendicular magnetic anisotropy; Resonant frequency; Temperature dependence;
Journal_Title :
Magnetics, IEEE Transactions on
