A crystalline form of a \u03b3-aminobutyric acid analog, and methods of preparing same, are provided. When the cap is pressed onto a nozzle surface with the nozzle aligned with a center of a covering portion, a lip continuously contacts the surrounding of an opening of the nozzle, thereby forming a sealed space on the surface formed with the opening of the nozzle. Ar gas is then flown into the sputtering chamber to sputter deposit a first refractory metal-silicon-nitrogen layer on the substrate from a refractory metal silicide target, or from two targets of a refractory metal and a silicon. Furthermore, an electronics board is activated with a transponder key and controls operation of the lock by deactivating and subsequently activating a blocking mechanism formed by a motor that actuates a punch via a gear mechanism.