Aggregate frequency width, nuclear hyperfine coupling and Jahn–Teller effect of Cu²⁺impurity ion ESR in SrLaAlO₄dielectric resonator at 20 millikelvin

Abstract

The impurity paramagnetic ion, [Formula: see text] substitutes Al in the [Formula: see text] single crystal lattice, this results in a [Formula: see text] elongated octahedron, and the resulting measured g-factors satisfy four-fold axes variation condition. The aggregate frequency width of the electron spin resonance with the required minimum level of impurity concentration has been evaluated in this single crystal [Formula: see text] at 20 millikelvin. Measured parallel hyperfine constants, [Formula: see text], were determined to be [Formula: see text] and [Formula: see text] at [Formula: see text] for the nuclear magnetic quantum number [Formula: see text], and [Formula: see text] respectively. The anisotropy of the hyperfine structure reveals the characteristics of the static Jahn-Teller effect. The second-order-anisotropy term, [Formula: see text], is significant and cannot be disregarded, with the local strain dominating over the observed Zeeman-anisotropy-energy difference. The Bohr electron magneton, [Formula: see text], (within [Formula: see text] so-called experimental error) has been found using the measured spin-Hamiltonian parameters. Measured nuclear dipolar hyperfine structure parameter [Formula: see text] shows that the mean inverse third power of the electron distance from the nucleus is [Formula: see text] a.u. for [Formula: see text] ion in the substituted [Formula: see text] ion site assuming nuclear electric quadruple moment [Formula: see text] barn.

A Rare Natural Benzo[k,l]xanthene as a Turn-Off Fluorescent Sensor for Cu2+ Ion

“…In this geometry, the copper is complexed in a tetragonally elongated octahedral complex, where two oxygen (O65 and O66) of the same molecule of compound 1 and two oxygen atoms belonging to the other two molecules (O26 and O106) are lying in the xy plane, and the remaining O25 and O105 are located in the z -axis. The elongated octahedral is due to the Jahn–Teller effect that is often encountered in octahedral complexes of the transition metals and is very common in six-coordinate Cu 2+ complexes [ 31 , 32 ]. According to the crystal field theory, the complexes of copper are principally square planar, with the odd electron occupying the d x 2 - y 2 orbital; any addition ligands available would take up the fifth and sixth coordination positions, but because the d z 2 always contains a pair of electrons, usually the fifth and sixth ligands (O25 and O105 in the case of Cu 2+ /compound 1 complex) will not be able to approach the copper as closely as the ligands in the plane [ 33 ].…”

Ultrasensitive multi-mode ESR probed ferromagnetic two-level system of $Mn^{4+}$ impurity ion in the insulated $MnO_6$ complex of $SrLaAlO_4$ at $20~mK$

“…The system can lift degeneracy resulting charge or spin ordering of manganese ion 44,45 . Crystal distortion relates to Jahn-Teller distortion 46 , and metal-ligand charge transfer with orbital ordering plays an essential role in stabilizing ferromagnetic states 10,28,45 .…”

Rigorous ESR spectroscopy of Fe3+ impurity ion with oxygen vacancy in ferroelectric SrTiO3 crystal at 20 mK

“…Where V s is the mode volume, T s is the sample temperature, S is the electron effective spin, g e is the electron g-factor, β is the Bohr electron magneton, µ • is the magnetic permeability of free space, ω is the resonance frequency, η is the filling factor, P n is the noise power at the detector due to all sources, P is the microwave input power, and ∆ω is the width of aggregated spin frequency at resonance which is depended on the shape-function f (ω) normalized as ∞ 0 f (ω)∂ω = 1 for a wide range of Larmor precession (ω L ) of magnetic dipoles [21]. Significant output (transmission) occurs only at resonance in a very narrow frequency width ∆ω in the region ω ≈ ω L at ESR [29,31]. This frequency width is about 300 000 Hz in the ferroelectric anisotropy of the crystal SrTiO 3 crystal (see figures 1-3), and Q-factor of the selected modes were about 1000 at 20 mK temperature.…”