Lattice energies ΔLHθ of lanthanide orthophosphates, LnPO4 (Ln=Ce-Lu, excluding Pm) have been determined from the Born-Haber cycle and compared with those calculated by other methods. The Born-Haber cycle results in close values of ΔLHθ to those obtained after an empirical equation proposed by Glasser and Jenkins. It has been found that: (i) the partial derivative of the lattice enthalpies to t...

X-ray measurements were carried out in order to study the spontaneous radiation effects of alianite, gadolinite and monazite on their structures. It was found that the first two gave the experimental evidences of either expan sions from or destruction of their normal lattice structures, while the last one showed lattice expansion only. Heat treatments of these minerals in the vacuum caused them...

This paper is concerned with the approach followed in Western Australian for dealing with the environmental hazards of ionising radiation associated with the mining and processing of titaniferous minerals contained in mineral sands deposits. There is a growing public awareness of the risks posed by one of these minerals, monazite, which emits low levels of radiation as it contains thorium and u...

The Dabie Shan Ultrahigh-Pressure Metamorphic (UHPM) Belt occupies the suture between the Yangtze and Sino-Korean blocks in east-central China. The timing of UHPM in the Dabie belt is controversial, and most recent data come from dating of zircons. Monazite has recently been recognized as useful for dating of multiple tectonic events due to its preservation of multiple growth zones, and monazit...

Zircon and monazite from three restitic enclaves and one host dacite have been dated by ion microprobe (SHRIMP), with the aim of characterising their Miocene history and defining the timing relationships between crustal melting and eruption in the high-K calc-alkaline volcanics of the Neogene Volcanic Province of SE Spain. The studied samples are from the volcanic edifices of El Joyazo (Cerro d...

Electron probe microanalysis (EPMA) of accessory minerals such as monazite, xenotime, and thorite for minorand trace-element concentrations and geochronology, requires consideration of beam irradiation effects (increasing heat and charge) as higher current densities and lengthy counting times are employed, and requires careful, detailed assessment of background intensities and interferences. A ...