title: Magnetic-field-induced optical bistability in multifunctional Gd(2)O(3):Er(3+)Yb(3+) upconversion nanophosphor.
abstract: The effect of an external magnetic field (0-1 T) on the upconversion emission (lambda(exc)=976 nm) of Gd(2)O(3):Er(3+)Yb(3+) nanocrystalline phosphor has been studied. Optical bistability (hysteresis behavior in the intensity of the optical emission) for different transitions of the Er(3+) ion has been observed for a complete cycle of the magnetic field between 0 and 1 T. The phosphor shows paramagnetic behavior, consistent with the presence of Gd(3+) ions, at room temperature. Interaction between induced magnetization in the Gd(2)O(3) host and the intrinsic magnetic moment of the nanosized clusters of Er(3+) and Yb(3+) ion pairs is proposed to be responsible for the hysteresis behavior.
authors.affiliation: Laser and Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, Varanasi-05, India.
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Singh
authors.forename: Kaushal
authors.initials: K
authors.lastname: Kumar
authors.forename: Manish K
authors.initials: MK
authors.lastname: Srivastava
authors.forename: Devendra K
authors.initials: DK
authors.lastname: Rai
authors.forename: Shyam B
authors.initials: SB
authors.lastname: Rai