Annealing of radiomanganese in irradiated potassium perganganate under different circumstances

Hot Atom Chemistry in Oxyanion Targets: Behaviour of Recoil 56Mn in Lanthanum Permanganate

“…Table 1). Almost a similar trend of retention on pre-activation heat treatment has been shown by other permanganates [4,7,8]. However, there are a few instances of higher retention values in case of pre-activation heated targets [9,10] than post-activation heated ones.…”

“…1 and 2). Although the nature of the curves are similar to earlier studies [3,4,[10][11][12] the Saturation time for other permanganates [4] are different. Such dilferences have been seen as a consequence of the varying degree of solid State reactions which are largely influenced by the nature of crystal defects [3, 4, 13 -15] (inherent and radiation induced) lattice energy, crystal packing, density etc.…”

“…Isotherms obtained in the two cases follow the classical pattem, i.e., an initial sharp rise followed by a temperature dependent pseudoplateau. Other oxyanions [4,9,11] have also shown similar trends of retention following heat treatment. In both cases limiting Saturation retention values of (45% max) at 373 K for preactivation heated sample and (60% max) for post-activation heated sample were obtained in ca 40 min of heating (cf.…”

“…The initial retention value for Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 7/23/15 9:26 AM recoil '^Mn in lanthanum permanganate irradiated at room temperature was found to be 25%. Although the majority of permanganates studied so far have yielded IG wer retentions values (4-21%) [4,6], except cesium permanganate which gave ca 31% retention on Irradiation at ambient temperature. Pre-activation heating of the target at different temperatures for desired lengths of time gave lower retention values than those obtained at corresponding temperatures for similar lengths of heating time in case of post activation heated targets (cf.…”

“…), bring about marked alteration in the identity of these solid State lattice stable precursors. Nevertheless, besides, the absence of sufficiently sensitive analytical tools to make in situ studies, scientists have industriously tried to probe the phenomenon indirectly [2], Although the (n,}*) event has been studied in a variety of permanganates [3,4], to our knowledge no attempt seems to have been made in the case of the rare earth permanganates. This is, perhaps, the first report on the (n,y) study on recoil in lanthanum permanganate, where we have tried to analyse the observed results in the light of recent ideas which would help in understanding the recoil stabilization mechanism in permanganates, in particular and in oxyanion targets in general.…”