Absorption Spectrum and Zeeman Effect of Ho³⁺ in YPO₄

Abstract

The optical absorption spectra of trivalent holmium in single crystals of HoPO, and (I-, Ho)PO, have been measured in the range from 15000 to 29000 em-l including the Zeeman effect of the ground level 51: and the two excited levels 3K; and 5Gk at 85 and 4.2 OK. The splitting factors of the degenerate components of the ground level and the level 3Ki indicate a small mixing of the states Y~J M with different M . With this fact some special features of the transitions between these two levels can be explained qualitatively. Es wurden die Absorptionsspektren des dreiwertigen Holmiums in Einkristallen vonHoPO, und (Y, Ho)PO, zwischen 15000 und 29000 cm-l und der Zeeman-Effekt des Gririidterms 51k und der beiden angeregten Terme 3K; und 5Gk bei 85 und 4,2 OK gemessen. Die Aufspaltungsfaktoren des Grundterms und des Terms 3Ki deuten auf eine geringe Durchmischung der Zustinde yY J M mit unterschiedlichem $1 hin. Damit lassen sich einige Besonderheiten der Ubergange zwischen diesen beiden Termen qualitativ erklaren.

Crystal Field Parameters of Ho3+ in YPO4

“…I n most cases there are two possible sets, which mainly differ in the value of A:(r4). The sets with the slightly higher standard deviation give a better description of theZeeman splitting factors defined in [9]. We prefer these latter sets, since obviously they are a better representation of the eigenfunctions of the crystal field components.…”

“…Recently, Beclcer et al [9] have published measured crystal field splittings of Ho3+ in YPO,. I n this paper we present the parameters fitted to these splittings.…”

“…[9] are in first approximation described by the crystal potential operator, which is most conveniently written in the formThe crystal field splittings of Ho3+ on a site of symmetry 32m v = A: ( T 2 ) e, z o; + A: (?4) ey 0: + + A: ( T 6 ) e; o; + A: +4) et 0; + A: (F) e; 0: . The matrix elements of this operator between the states of the free ion have been calculated by the operator equivalent method [lo, 111.…”

Absorption and Fluorescence Spectra of Tm3+ in YVO4 and YPO4

“…Within a group of transitions there are very great differences in intensity of the individual transitions. This can be interpreted (as in [S]) by the assumption that the lowest component I of the ground level and various components of excited levels contain mainly one free ion ?pYJM and that the part V5 of the crystal field operator (equation (1) of [8]) is very small.…”

Optical Absorption Intensities of Ho3+ in YPO4

“…Assuming that the splitting of the admixed configurations is small compared to their distances to the ground configuration 4f10, the matrix elements of the electric dipole operator can be calculated with the unperturbed 4 f10 states [8] the first sum is running over k = 3,5, 7 and q = 2, 6 (q 5 k).…”