Optically detected magnetic resonance via the magnetic circular dichroism of absorption of cerium impurities in bulk paramagnetic terbium gallium garnet

Abstract

The paramagnetic resonance of dilute Ce 3+ ions in the bulk paramagnetic host Tb 3 Ga 5 O 12 is separated from the host response by means of optically detected magnetic resonance (ODMR) using the magnetic circular dichroism (MCD) of the absorption. This result shows that it is possible in principle to extend by means of the ODMR of the absorption the regime of paramagnetic resonance detection of impurity ions to magnetic hosts, which strongly interact with the microwave field and, hence, make the impurity signals unobservable by means of conventional EPR. The observed ODMR signals are attributed to Tb 3+ and Ce 3+ ions by correlation with the optical bands of these species. By means of ODMR via the Faraday effect it is shown that this effect is due to transitions between Tb levels. The identification of the observed magnetic resonance structures is confirmed by calculations based on known information on Tb 3+ and Ce 3+ in diamagnetic hosts. The role of molecular fields is discussed.

The Gd–Ce Cross-Relaxation Effects in ODMR via Ce3+ Emission in Garnet Crystals

“…ions in garnet crystals exhibit strong magnetic circular dichroism (MCD) in absorption [29,30]. In [30], EPR of cerium ions has been observed via MCD in Y 3 Al 5 O 12, and the MCD bands at 227, 270, 338, and 458.5 nm have been definitely attributed to Ce 3?…”

Optical and magnetooptical properties of Ho3+:YGG

“…At the same time, it is well known that the magnetooptic and optic (mainly, luminescent) studies of Ho 3+ in garnets have been rather limited, in contrast to most other heavy RE 4–7. Mainly, this is related to the specific features of the Stark splitting of the energy spectrum of the non‐Kramers Ho 3+ ion (with an even number of electrons in the unfilled 4f‐shell) in the garnet structure.…”

Magnetooptics of quintet states of Tb3+ ion in terbium–yttrium aluminum garnet

“…Difficulties in interpreting the spectra of the non-Kramers RE ions can be overcome by studying the forbidden (in the electrodipole approximation) transitions with the methods of differential magnetoopti-cal spectroscopy, namely the methods of magnetic circular dichroism (MCD) [9,13,14] and magnetic circular polarization of luminescence (MCPL) [15,16]. The large amount of information provided by the magnetooptical study methods is connected with the fact that the behavior of the MCD and MCPL spectra in the vicinity of the 4f-4f transition is defined unambiguously by the features of Stark splitting of the energy spectrum of the non-Kramers RE ion multiplets.…”