title: Heat Capacities of Natural Antlerite and Brochantite at Low Temperature.
abstract: The investigation of a magnetic component of the heat capacity of natural samples of copper sulfates antlerite Cu3SO4(OH)4in the temperature range below 40 K and brochantite Cu4SO4(OH)6below 55 K has been carried out. A regular component of the heat capacity has been calculated from experimental data of adiabatic calorimetry. In the low-temperature area of (0 to 55) K two peaks of magnetic heat capacity for brochantite have been registered. The contributions of anomalous component ΔStrinto entropy of the minerals are (11 ± 3) J·mol-1·K-1for antlerite and (5.3 ± 1.5) J·mol-1·K-1for brochantite.
authors.affiliation: Institute of Complex Development of Mineral Resources , Ippodromnaya Street 5, Karaganda, 100019, Kazakhstan.
authors.forename: Mira R
authors.initials: MR
authors.lastname: Bissengaliyeva
authors.forename: Nuraly S
authors.initials: NS
authors.lastname: Bekturganov
authors.forename: Daniil B
authors.initials: DB
authors.lastname: Gogol
authors.forename: Shynar T
authors.initials: ST
authors.lastname: Taimassova
authors.forename: Temirgaly A
authors.initials: TA
authors.lastname: Koketai
authors.forename: Michael A
authors.initials: MA
authors.lastname: Bespyatov