title: Side-hole to anti-hole conversion in time-resolved transient spectral hole-burning of emerald: ground state level versus excited state population storage in low magnetic fields.
abstract: Time-resolved transient spectral hole-burning experiments in zero field and in low magnetic fields B( parallelc) are reported for the chromium(III) R(1)-line, 2A((2)E)<-- 2A((4)A(2)) of Chatham lab created emerald, Be(3)Al(2)Si(6)O(18)ratio Cr(III)(0.0017% per weight), in the temperature range of 3 to 12 K. In low magnetic fields and temperatures >5 K conversion of side-holes to anti-holes is observed with progressing time. Anti-holes are due to the population stored in ground state levels. The dynamics of the hole pattern can be well modelled by a set of coupled differential equations for the levels of the (4)A(2) and (2)E multiplets. The measurements allow the simultaneous determination of g-factors and spin-lattice relaxation rates in the excited state and the ground state. At 6 K the relaxation times between the split +/-1/2 2A((2)E) excited state levels and +/-3/2 2A((4)A(2)) levels of the ground state are about 0.16 ms and 9 ms, respectively. From the temperature dependence it follows that the spin-lattice relaxation rates are dominated by Orbach processes in the experimental temperature range.
authors.affiliation: School of Physical, Environmental and Mathematical Sciences, University College, The University of New South Wales, ADFA, Canberra, ACT 2600, Australia.
authors.forename: Brendan F
authors.initials: BF
authors.lastname: Hayward
authors.forename: Hans
authors.initials: H
authors.lastname: Riesen
mesh_terms: D000535:Aluminum / Q000737:chemistry; D001608:Beryllium / Q000737:chemistry; D002857:Chromium / Q000737:chemistry; D008280:Magnetics; D010100:Oxygen / Q000737:chemistry; D016062:Porosity; D012825:Silicon / Q000737:chemistry; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D002857:Chromium; D000535:Aluminum; D001608:Beryllium; D010100:Oxygen; D012825:Silicon